Hmmm, nope it didn't work, but thanks.

I replaced all my previous code with just
echo ' (Posts: '.$cur_post['num_posts'].')';
and now the page displays correctly, but the guest posts displays the number 0 when the post count of user ID 4 (the "guest" account) is not 0.

Ok, but it's modified a bit:

<?php
/***********************************************************************

  Copyright (C) 2002-2005  Rickard Andersson (rickard@punbb.org)

  This file is part of PunBB.

  PunBB is free software; you can redistribute it and/or modify it
  under the terms of the GNU General Public License as published
  by the Free Software Foundation; either version 2 of the License,
  or (at your option) any later version.

  PunBB is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  MA  02111-1307  USA

************************************************************************/


define('PUN_ROOT', './');
require PUN_ROOT.'include/common.php';


if ($pun_user['g_read_board'] == '0')
    message($lang_common['No view']);


$action = isset($_GET['action']) ? $_GET['action'] : null;
$id = isset($_GET['id']) ? intval($_GET['id']) : 0;
$pid = isset($_GET['pid']) ? intval($_GET['pid']) : 0;
if ($id < 1 && $pid < 1)
    message($lang_common['Bad request']);

// Load the viewtopic.php language file
require PUN_ROOT.'lang/'.$pun_user['language'].'/topic.php';


// If a post ID is specified we determine topic ID and page number so we can redirect to the correct message
if ($pid)
{
    $result = $db->query('SELECT topic_id FROM '.$db->prefix.'posts WHERE id='.$pid) or error('Unable to fetch post info', __FILE__, __LINE__, $db->error());
    if (!$db->num_rows($result))
        message($lang_common['Bad request']);

    $id = $db->result($result);

    // Determine on what page the post is located (depending on $pun_user['disp_posts'])
    $result = $db->query('SELECT id FROM '.$db->prefix.'posts WHERE topic_id='.$id.' ORDER BY posted') or error('Unable to fetch post info', __FILE__, __LINE__, $db->error());
    $num_posts = $db->num_rows($result);

    for ($i = 0; $i < $num_posts; ++$i)
    {
        $cur_id = $db->result($result, $i);
        if ($cur_id == $pid)
            break;
    }
    ++$i;    // we started at 0

    $_GET['p'] = ceil($i / $pun_user['disp_posts']);
}

// If action=new, we redirect to the first new post (if any)
else if ($action == 'new' && !$pun_user['is_guest'])
{
    $result = $db->query('SELECT MIN(id) FROM '.$db->prefix.'posts WHERE topic_id='.$id.' AND posted>'.$pun_user['last_visit']) or error('Unable to fetch post info', __FILE__, __LINE__, $db->error());
    $first_new_post_id = $db->result($result);

    if ($first_new_post_id)
        header('Location: viewtopic.php?pid='.$first_new_post_id.'#p'.$first_new_post_id);
    else    // If there is no new post, we go to the last post
        header('Location: viewtopic.php?id='.$id.'&action=last');

    exit;
}

// If action=last, we redirect to the last post
else if ($action == 'last')
{
    $result = $db->query('SELECT MAX(id) FROM '.$db->prefix.'posts WHERE topic_id='.$id) or error('Unable to fetch post info', __FILE__, __LINE__, $db->error());
    $last_post_id = $db->result($result);

    if ($last_post_id)
    {
        header('Location: viewtopic.php?pid='.$last_post_id.'#p'.$last_post_id);
        exit;
    }
}


// Fetch some info about the topic
if (!$pun_user['is_guest'])
    $result = $db->query('SELECT t.subject, t.closed, t.num_replies, t.sticky, f.id AS forum_id, f.forum_name, f.moderators, fp.post_replies, s.user_id AS is_subscribed FROM '.$db->prefix.'topics AS t INNER JOIN '.$db->prefix.'forums AS f ON f.id=t.forum_id LEFT JOIN '.$db->prefix.'subscriptions AS s ON (t.id=s.topic_id AND s.user_id='.$pun_user['id'].') LEFT JOIN '.$db->prefix.'forum_perms AS fp ON (fp.forum_id=f.id AND fp.group_id='.$pun_user['g_id'].') WHERE (fp.read_forum IS NULL OR fp.read_forum=1) AND t.id='.$id.' AND t.moved_to IS NULL') or error('Unable to fetch topic info', __FILE__, __LINE__, $db->error());
else
    $result = $db->query('SELECT t.subject, t.closed, t.num_replies, t.sticky, f.id AS forum_id, f.forum_name, f.moderators, fp.post_replies, 0 FROM '.$db->prefix.'topics AS t INNER JOIN '.$db->prefix.'forums AS f ON f.id=t.forum_id LEFT JOIN '.$db->prefix.'forum_perms AS fp ON (fp.forum_id=f.id AND fp.group_id='.$pun_user['g_id'].') WHERE (fp.read_forum IS NULL OR fp.read_forum=1) AND t.id='.$id.' AND t.moved_to IS NULL') or error('Unable to fetch topic info', __FILE__, __LINE__, $db->error());

if (!$db->num_rows($result))
    message($lang_common['Bad request']);

$cur_topic = $db->fetch_assoc($result);

// Sort out who the moderators are and if we are currently a moderator (or an admin)
$mods_array = ($cur_topic['moderators'] != '') ? unserialize($cur_topic['moderators']) : array();
$is_admmod = ($pun_user['g_id'] == PUN_ADMIN || ($pun_user['g_id'] == PUN_MOD && array_key_exists($pun_user['username'], $mods_array))) ? true : false;

// Can we or can we not post replies?
if ($cur_topic['closed'] == '0')
{
    if (($cur_topic['post_replies'] == '' && $pun_user['g_post_replies'] == '1') || $cur_topic['post_replies'] == '1' || $is_admmod)
        $post_link = '<a href="post.php?tid='.$id.'">'.$lang_topic['Post reply'].'</a>';
    else
        $post_link = ' ';
}
else
{
    $post_link = $lang_topic['Topic closed'];

    if ($is_admmod)
        $post_link .= ' / <a href="post.php?tid='.$id.'">'.$lang_topic['Post reply'].'</a>';
}


// Determine the post offset (based on $_GET['p'])
$num_pages = ceil(($cur_topic['num_replies'] + 1) / $pun_user['disp_posts']);

$p = (!isset($_GET['p']) || $_GET['p'] <= 1 || $_GET['p'] > $num_pages) ? 1 : $_GET['p'];
$start_from = $pun_user['disp_posts'] * ($p - 1);

// Generate paging links
$paging_links = $lang_common['Pages'].': '.paginate($num_pages, $p, 'viewtopic.php?id='.$id);


if ($pun_config['o_censoring'] == '1')
    $cur_topic['subject'] = censor_words($cur_topic['subject']);


$quickpost = false;
if ($pun_config['o_quickpost'] == '1' &&
    !$pun_user['is_guest'] &&
    ($cur_topic['post_replies'] == '1' || ($cur_topic['post_replies'] == '' && $pun_user['g_post_replies'] == '1')) &&
    ($cur_topic['closed'] == '0' || $is_admmod))
{
    $required_fields = array('req_message' => $lang_common['Message']);
    $quickpost = true;
}

if (!$pun_user['is_guest'] && $pun_config['o_subscriptions'] == '1')
{
    if ($cur_topic['is_subscribed'])
        // I apologize for the variable naming here. It's a mix of subscription and action I guess :-)
        $subscraction = '<p class="subscribelink clearb">'.$lang_topic['Is subscribed'].' - <a href="misc.php?unsubscribe='.$id.'">'.$lang_topic['Unsubscribe'].'</a></p>'."\n";
    else
        $subscraction = '<p class="subscribelink clearb"><a href="misc.php?subscribe='.$id.'">'.$lang_topic['Subscribe'].'</a></p>'."\n";
}
else
    $subscraction = '<div class="clearer"></div>'."\n";

$page_title = pun_htmlspecialchars($pun_config['o_board_title'].' / '.$cur_topic['subject']);
define('PUN_ALLOW_INDEX', 1);
require PUN_ROOT.'header.php';

?>
<div class="linkst">
    <div class="inbox">
        <!--p class="pagelink conl"><?php echo $paging_links ?></p-->
        <p class="postlink conr"><?php echo $post_link ?></p>
        <ul><li><a href="index.php"><?php echo $lang_common['Index'] ?></a></li><li> » <a href="viewforum.php?id=<?php echo $cur_topic['forum_id'] ?>"><?php echo pun_htmlspecialchars($cur_topic['forum_name']) ?></a></li><li> » <?php echo pun_htmlspecialchars($cur_topic['subject']) ?></li></ul>
        <div class="clearer"></div>
    </div>
</div>

<?php


require PUN_ROOT.'include/parser.php';

$bg_switch = true;    // Used for switching background color in posts
$post_count = 0;    // Keep track of post numbers

// Retrieve the posts (and their respective poster/online status)
$result = $db->query('SELECT u.email, u.title, u.url, u.location, u.use_avatar, u.signature, u.email_setting, u.num_posts, u.registered, u.admin_note, p.id, p.poster AS username, p.poster_id, p.poster_ip, p.poster_email, p.message, p.hide_smilies, p.posted, p.edited, p.edited_by, g.g_id, g.g_user_title, o.user_id AS is_online FROM '.$db->prefix.'posts AS p INNER JOIN '.$db->prefix.'users AS u ON u.id=p.poster_id INNER JOIN '.$db->prefix.'groups AS g ON g.g_id=u.group_id LEFT JOIN '.$db->prefix.'online AS o ON (o.user_id=u.id AND o.user_id!=1 AND o.idle=0) WHERE p.topic_id='.$id.' ORDER BY p.id LIMIT '.$start_from.','.$pun_user['disp_posts'], true) or error('Unable to fetch post info', __FILE__, __LINE__, $db->error());

while ($cur_post = $db->fetch_assoc($result))
{
    $post_count++;
    $user_avatar = '';
    $user_info = array();
    $user_contacts = array();
    $post_actions = array();
    $is_online = '';
    $signature = '';

    // If the poster is a registered user.
    if ($cur_post['poster_id'] > 1)
    {
        $username = '<a href="profile.php?id='.$cur_post['poster_id'].'">';
        $user_title = get_title($cur_post);

        if ($pun_config['o_censoring'] == '1')
            $user_title = censor_words($user_title);

        // Format the online indicator
        $is_online = ($cur_post['is_online'] == $cur_post['poster_id']) ? ''.$lang_topic['Online'].'' : $lang_topic['Offline'];

        if ($pun_config['o_avatars'] == '1' && $cur_post['use_avatar'] == '1' && $pun_user['show_avatars'] != '0')
        {
            if ($img_size = @getimagesize($pun_config['o_avatars_dir'].'/'.$cur_post['poster_id'].'.gif'))
                $user_avatar = '<img src="'.$pun_config['o_avatars_dir'].'/'.$cur_post['poster_id'].'.gif" '.$img_size[3].' alt="" />';
            else if ($img_size = @getimagesize($pun_config['o_avatars_dir'].'/'.$cur_post['poster_id'].'.jpg'))
                $user_avatar = '<img src="'.$pun_config['o_avatars_dir'].'/'.$cur_post['poster_id'].'.jpg" '.$img_size[3].' alt="" />';
            else if ($img_size = @getimagesize($pun_config['o_avatars_dir'].'/'.$cur_post['poster_id'].'.png'))
                $user_avatar = '<img src="'.$pun_config['o_avatars_dir'].'/'.$cur_post['poster_id'].'.png" '.$img_size[3].' alt="" />';
        }
        else
            $user_avatar = '';

        // We only show location, register date, post count and the contact links if "Show user info" is enabled
        if ($pun_config['o_show_user_info'] == '1')
        {
            if ($cur_post['location'] != '')
            {
                if ($pun_config['o_censoring'] == '1')
                    $cur_post['location'] = censor_words($cur_post['location']);

                $user_info[] = '<dd>'.$lang_topic['From'].': '.pun_htmlspecialchars($cur_post['location']);
            }

            $user_info[] = '<dd>'.$lang_common['Registered'].': '.date($pun_config['o_date_format'], $cur_post['registered']);

            if ($pun_config['o_show_post_count'] == '1' || $pun_user['g_id'] < PUN_GUEST)
                $user_info[] = '<dd>'.$lang_common['Posts'].': '.$cur_post['num_posts'];

            // Now let's deal with the contact links (E-mail and URL)
if (($cur_post['email_setting'] == '0' && !$pun_user['is_guest']) || $pun_user['g_id'] < PUN_GUEST)
                $user_contacts[] = '<a href="mailto:'.$cur_post['email'].'">'.$lang_common['E-mail'].'</a>';
            else if ($cur_post['email_setting'] == '1' && !$pun_user['is_guest'])
                $user_contacts[] = '<a href="misc.php?email='.$cur_post['poster_id'].'">'.$lang_common['E-mail'].'</a>';

            if ($cur_post['url'] != '')
                $user_contacts[] = '<a href="'.pun_htmlspecialchars($cur_post['url']).'">'.$lang_topic['Website'].'</a>';
        }            






        if ($pun_user['g_id'] < PUN_GUEST)
        {
            $user_info[] = '<dd>IP: <a href="moderate.php?get_host='.$cur_post['id'].'">'.$cur_post['poster_ip'].'</a>';

            if ($cur_post['admin_note'] != '')
                $user_info[] = '<dd>'.$lang_topic['Note'].': <strong>'.pun_htmlspecialchars($cur_post['admin_note']).'</strong>';
        }
    }
    // If the poster is a guest (or a user that has been deleted)
    else
    {
        $username = pun_htmlspecialchars($cur_post['username']);
        $user_title = get_title($cur_post);

        if ($pun_user['g_id'] < PUN_GUEST)
            $user_info[] = '<dd>IP: <a href="moderate.php?get_host='.$cur_post['id'].'">'.$cur_post['poster_ip'].'</a>';

        if ($pun_config['o_show_user_info'] == '1' && $cur_post['poster_email'] != '' && !$pun_user['is_guest'])
            $user_contacts[] = '<a href="mailto:'.$cur_post['poster_email'].'">'.$lang_common['E-mail'].'</a>';
    }

    // Generation post action array (quote, edit, delete etc.)
    if (!$is_admmod)
    {
        if (!$pun_user['is_guest'])
            $post_actions[] = '<a href="misc.php?report='.$cur_post['id'].'">'.$lang_topic['Report'].'</a>';

        if ($cur_topic['closed'] == '0')
        {
            if ($cur_post['poster_id'] == $pun_user['id'])
            {
                if ((($start_from + $post_count) == 1 && $pun_user['g_delete_topics'] == '1') || (($start_from + $post_count) > 1 && $pun_user['g_delete_posts'] == '1'))
                    $post_actions[] = '<a href="delete.php?id='.$cur_post['id'].'">'.$lang_topic['Delete'].'</a>';
                if ($pun_user['g_edit_posts'] == '1')
                    $post_actions[] = '<a href="edit.php?id='.$cur_post['id'].'">'.$lang_topic['Edit'].'</a>';
            }

            if (($cur_topic['post_replies'] == '' && $pun_user['g_post_replies'] == '1') || $cur_topic['post_replies'] == '1')
                $post_actions[] = '<a href="post.php?tid='.$id.'&qid='.$cur_post['id'].'">'.$lang_topic['Quote'].'</a>';
        }
    }
    else
        $post_actions[] = '<li class="postreport"><a href="misc.php?report='.$cur_post['id'].'">'.$lang_topic['Report'].'</a>'.$lang_topic['Link separator'].'</li><li class="postdelete"><a href="delete.php?id='.$cur_post['id'].'">'.$lang_topic['Delete'].'</a>'.$lang_topic['Link separator'].'</li><li class="postedit"><a href="edit.php?id='.$cur_post['id'].'">'.$lang_topic['Edit'].'</a>'.$lang_topic['Link separator'].'</li><li class="postquote"><a href="post.php?tid='.$id.'&qid='.$cur_post['id'].'">'.$lang_topic['Quote'].'</a>';


    // Switch the background color for every message.
    $bg_switch = ($bg_switch) ? $bg_switch = false : $bg_switch = true;
    $vtbg = ($bg_switch) ? ' roweven' : ' rowodd';


    // Perform the main parsing of the message (BBCode, smilies, censor words etc)
    $cur_post['message'] = parse_message($cur_post['message'], $cur_post['hide_smilies']);

    // Do signature parsing/caching
    if ($cur_post['signature'] != '' && $pun_user['show_sig'] != '0')
    {
        if (isset($signature_cache[$cur_post['poster_id']]))
            $signature = $signature_cache[$cur_post['poster_id']];
        else
        {
            $signature = parse_signature($cur_post['signature']);
            $signature_cache[$cur_post['poster_id']] = $signature;
        }
    }

?>




//I'm pretty sure I didn't modify anything above this point.



<div id="p<?php echo $cur_post['id'] ?>" class="blockpost<?php echo $vtbg ?><?php if (($post_count + $start_from) == 1) echo ' firstpost'; ?>">
    <h2><span>

<a href="viewtopic.php?pid=<?php echo $cur_post['id'].'#p'.$cur_post['id'] ?>">#<?php echo ($start_from + $post_count) ?></a> 

<strong>



<?php
if ($user_title == $lang_common['Administrator'])
{
echo $username.'<font color="'.$lang_common['Admin Title Color'].'">'.pun_htmlspecialchars($cur_post['username']).'</font></a>';
}
else if ($user_title == $lang_common['Moderator'])
{
echo $username.'<font color="'.$lang_common['Mod Title Color'].'">'.pun_htmlspecialchars($cur_post['username']).'</font></a>';
} 
else if($cur_post['num_posts'] >= 500)
{
echo $username.'<font color="'.$lang_common['Elite Title Color'].'">'.pun_htmlspecialchars($cur_post['username']).'</font></a>';
}
else if($cur_post['num_posts'] >= 10)
{
echo $username.'<font color="'.$lang_common['Member Title Color'].'">'.pun_htmlspecialchars($cur_post['username']).'</font></a>';
}
else if($user_title == $lang_common['Guest'])
{
echo "Guest";
}
else
{
echo $username.'<font color="'.$lang_common['Newmember Title Color'].'">'.pun_htmlspecialchars($cur_post['username']).'</font></a>';
}
?>
</strong>

<?php
$userid=4;
$query = $db->query('SELECT num_posts FROM '.$db->prefix.'users WHERE id='.$userid);
$guestPosts = $db->result($query);

//if poster is a guest
if($user_title == $lang_common['Guest'])
{
echo ' (Posts: '.$guestPosts.')';
}

//if poster is a member
else
{
echo ' (Posts: '.$cur_post['num_posts'].')';
}
?>

  ~<?php echo format_time($cur_post['posted']) ?>


<span class="conr"><?php echo (count($post_actions)) ? ''.implode($lang_topic['Link separator'].'', $post_actions).''."\n" : '<div> </div></div>'."\n" ?></span>



</span>         
</h2>
    <div class="box">
        <div class="inbox">
            
            <div class="postright">
                <h3><?php if (($post_count + $start_from) > 1) echo ' Re: '; ?><?php echo pun_htmlspecialchars($cur_topic['subject']) ?></h3>
                <div class="postmsg">
                    <?php echo $cur_post['message']."\n" ?>
                </div>

            </div>

</div>
    </div>
</div>

<?php

}

?>
<div class="postlinksb">
    <div class="inbox">
        <p class="postlink conr"><?php echo $post_link ?></p>
        <p class="pagelink conl"><?php echo $paging_links ?></p>
        <!--ul><li><a href="index.php"><?php echo $lang_common['Index'] ?></a></li><li> » <a href="viewforum.php?id=<?php echo $cur_topic['forum_id'] ?>"><?php echo pun_htmlspecialchars($cur_topic['forum_name']) ?></a></li><li> » <?php echo pun_htmlspecialchars($cur_topic['subject']) ?></li></ul-->
        <?php echo $subscraction ?>
    </div>
</div>

<?php

// Display quick post if enabled
if ($quickpost)
{

?>
<div class="blockform">
    <h2><span><?php echo $lang_topic['Quick post'] ?></span></h2>
    <div class="box">
        <form method="post" action="post.php?tid=<?php echo $id ?>" onsubmit="this.submit.disabled=true;if(process_form(this)){return true;}else{this.submit.disabled=false;return false;}">
            <div class="inform">
                <fieldset>
                    <legend><?php echo $lang_common['Write message legend'] ?></legend>
                    <div class="infldset txtarea">
                        <input type="hidden" name="form_sent" value="1" />
                        <input type="hidden" name="form_user" value="<?php echo (!$pun_user['is_guest']) ? pun_htmlspecialchars($pun_user['username']) : 'Guest'; ?>" />
                        <label><textarea name="req_message" rows="7" cols="75" tabindex="1"></textarea></label>
                        <ul class="bblinks">
                            <li><a href="help.php#bbcode" onclick="window.open(this.href); return false;"><?php echo $lang_common['BBCode'] ?></a>: <?php echo ($pun_config['p_message_bbcode'] == '1') ? $lang_common['on'] : $lang_common['off']; ?></li>
                            <li><a href="help.php#img" onclick="window.open(this.href); return false;"><?php echo $lang_common['img tag'] ?></a>: <?php echo ($pun_config['p_message_img_tag'] == '1') ? $lang_common['on'] : $lang_common['off']; ?></li>
                            <li><a href="help.php#smilies" onclick="window.open(this.href); return false;"><?php echo $lang_common['Smilies'] ?></a>: <?php echo ($pun_config['o_smilies'] == '1') ? $lang_common['on'] : $lang_common['off']; ?></li>
                        </ul>
                    </div>
                </fieldset>
            </div>
            <p><input type="submit" name="submit" tabindex="2" value="<?php echo $lang_common['Submit'] ?>" accesskey="s" /></p>
        </form>
    </div>
</div>
<?php

}

// Increment "num_views" for topic
$low_prio = ($db_type == 'mysql') ? 'LOW_PRIORITY ' : '';
$db->query('UPDATE '.$low_prio.$db->prefix.'topics SET num_views=num_views+1 WHERE id='.$id) or error('Unable to update topic', __FILE__, __LINE__, $db->error());

$forum_id = $cur_topic['forum_id'];
$footer_style = 'viewtopic';
require PUN_ROOT.'footer.php';

Basically what I'm trying to do is have the group "Guest" have a post count, so whenever a guest posts, it increments the post count +1 of a user I made specifically for this purpose, and this user's ID is 4 (this part is already working). Therefore, whenever a guest posts, I want this Guest post count to appear under the guest, so I placed the code here in viewtopic.php:

<?php
$userid=4;
$query = $db->query('SELECT num_posts FROM '.$db->prefix.'users WHERE id='.$userid);
$guestPosts = $db->result($query);

//if poster is a guest
if($user_title == $lang_common['Guest'])
{
echo ' (Posts: '.$guestPosts.')';
}

//if poster is a member
else
{
echo ' (Posts: '.$cur_post['num_posts'].')';
}
?>

So, I put the code above where the post count is echo'd in viewtopic.php, but it doesn't display the page correctly..

Hey, thanks for the quick reply. Unfortunately it's still not working, although it's not giving my any syntax errors.

edit:
ok, I may have made some progress, but right now it still doesn't work:

$userid=4;
$query = $db->query('SELECT num_posts FROM '.$db->prefix.'users WHERE id='.$userid);
$query = $db->result($query);
echo $query;

I'm trying to put this code on viewtopic.php, but only the first post in a topic shows up..

Hi, I know this may sound like a strange request, but how would I extract the post count of just one user from the forum database?
The user id is 4, and so I believe that means the post count for that user is stored in the 4th row of "num_posts", but I need to know how to use php to echo this post count value onto one of the forum pages. Any help would be appreciated.