Add donators system

[Areku]

Hi!

I've seen in one of the boards of one of you a system where, after paying a fixed amount every xx time (months, years) you get a COLLABORATOR sign in the postbit plus some site advantages (like @domain.com email, extra privileges, etc...)

I'm willing to set up something like this but I can't find the hack that would allow/control this.

I've seen some "doantors" hacks but they don't seem to fit what I'm seeking.

Any advices please?

Thanks!