members with a password can join a group

hey, I have a forum, and in that forum, only members of a certain group can see certain forums/topics... As it is now, ppl that join subscribe to this special group, and I approve or disprove them to join.. This works, but incredibly poorly... Is there a way to create a group, or something like a group that requires a password, but with that password, members can join the group with that username without my consent? (cuz as it is now, they apply, and it takes a while, sometimes a few days before I approve them to join)

Oh, and I can't use a regular open group, cuz this group is exclusive... I don't want every member to be able to join. Thanks!

Hi!

This is not possible I'm afraid, but feel free to suggest in the suggestions section if you wish.