Can We Block A user from entering a group?

Hi there ,
I was just wondering if I could block a user from entering a group , because there is a member in my forum which I've been removing from member list , and the member list requires everyone to have 1 post , so he just has to post once and he's back a member again , so is there any way I can block the user from doing so without banning?

Block the user from what?

I can't really follow.. but if you mean that if you have an auto subscribe group(with certain amount of post to get into there), you can't block a member from entering to that group when they reached the achievement post, you have to remove them manually..

So there's no way I can remove him automatically or block him?

Nope.