[Mod Request] Non Group Member can see forum but not read it

I'm interested in having the ability to make a forum link show up on the forum page, but when clicked inform the guest they are not in the required group to read this forum.  I'm interested in this, because my site has a few forums that only a special group can see, but other people to the site don't even know the additional forums exists.  I don't want to make them readable because they contain personal info like phone numbers and addresses of people in this group.  People in the specific group have to be granted permission to be in this group to see these forums.

I've searched, but couldn't find anything like this.  I'm interested to know if anyone can do this or help me figure out what I would need to do.  thanks