Newly registered have to post in certain forum
 

I know something like this exists but I can't find it anymore.

I need a hack, that limits new users to a certain forum untill they made a post there. They may see and visit the complete forum but must not be able to write pm's and post anywhere else then in that welcome section.
I don't mean the Cyb's limit access based on postcount, because that hack can't do what we want.

Yes this can be done by accessmasks and usergroups but I would like to leave things as original as possible and I'm sure I've seen something like this in the past.

Can anybody point me to that hack please?

This would be done using the built in promotions system- set registered users to only be able to post in 1 forum, then setup a promotion to promote people to a new usergroup with full rights after 1 post.

Yes I know, but I don't want to do that via the promotion system, just because i have to use usergroups then again, setup rights for forums etc. Next to that it's for a forum I administer so I would like to leave it as original as possible.

I'm sure I've seen a mod which already had this option, but maybe it's too long ago.

Thank you for thinking about it though.