[How can i do this?] Creating social groups, displayed in postbit (4.x)

[Alex@bulletin]

Hello folks,

i'd like to realize the following:
Of course in vbulletin we can create social groups.
I need something that makes it possible to divide the social groups in two categories.
Groups of category 1 are normal groups to discuss and only shown in profile as usual
Groups of category 2 should be displayed in the postbit. My intention is, that users can create "societys" they belong to, and you can see this clubs in postbit.

e.g:
Alex@bulletin
Join Date: ....
and so one...
Clubs: Chess Club, Football Groupies etc.

Does somebody know a modification that can do this? Maybe a combination of two or more modifications. :)

Thanks for all good replies.