Permissions based on non vB-setting?

[Swedie]

Hey!

I have a problem where i need to assign permissions based on a value in a user field (a membership ID number).

The ID is at the moment checked towards an external database. If the ID is good I assign a Session value that gives access to certain forum IDs. For this I've written a PHP plugin, and a simple template based <if> statement).

But I would like to know if I can assign a user a certain Usergroup IF the given ID is good. That way I can create a usergroup that is allowed access to a forum based on the built in vBulletin permissions settings. This gives me a better overall control. Because right now the posts in a forum is still shown in Get new posts and other locations. Not until users click on the thread they are given the Message that they need to be authorized in order to view the thread / post in question.

I hope someone here knows what I mean and have a solution for me.