Integrating forums with start login

Now, my dear friends start a big project for my colleague and me.

We have downloaded PunBB and now intends to embark on a task that no one previously seems to have done. As much as I search on google so I do not find the answer, not even on PunBB.

I have searched high and low for weeks after a PHP developer who can integrate PunBB with start login and that seems to be quite impossible, I promise.

What should we do?
Well, we should integrate PunBB with the login on the homepage. When the user logs on to the start page so the user is also logged in the forum. The forum will only be visible to logged in members.

My guess is that this project will take maybe 2-3 weeks. There is one, only one person in Sweden that I have seen integrated PunBB, otherwise, I have never seen it.

Now for my question.
Is there anybody who has done this ever? Has anyone integrated a forum with a login on the homepage? For there is very little threads on the internet which could address this topic.