Unfortunately, what you're looking for doesn't exist. It would needed to be specifically coded for Vbulletin as what you are referring to is essentially a randomized method of choosing members to be able to register?
The problem with your idea is that there's no way to track who's already tried to register and who hasn't. The only conceivable way is to have cookies, but if you remove the cookies, the user can re-attempt to register and hope to get in again.
So essentially what I would suggest is limit registrations to the first 5000. Or use an invitation system, that's the only ways I see that would work for you.
|