You could use my mod.. and preset usergroups in admincp
then change the title with instructions in html format..
like
Enter wanted usergroup :
- 1 = wanker A group
- 2 = wanker B group
- 3 = wanker C group
and then the invitation codes just match accordingly,,
like 1 = wankerg group A, 2 group b etc etc.. ..
And it runs on vb 4...
https://vborg.vbsupport.ru/showthread.php?t=238681