create forums and/or under forums from one under external domain

[nick8362]

Good morning, I'm in search of a resolution to create forums and/or under forums from one under external domain.
I explain: I have a site on which automatically during the creation of your count (site of games MMO Cards), a count is also created on the forum (with connection auto if logué on the site etc). It is about an external module which I have develop. I search now the possibility of creating a private forum automatically for sure user (XP in 100 for instance give the possibility of creating a forum always from the site and not on forum)
Therefore my needs clearly are:
- creation of forum / sub-forum
- Creation of the group of linked user
- With permissions also (already defined on paper)

Thank you beforehand and excuse me for my Bad English