Thank you. That is useful. However, I still have 180 users that I have to get into that new group, which I have named "Private." I can find no way to do that other than adding each user individually/manually.
For example, all my 180 Users are "registered" because it's a semi-private forum with moderation. Is there a way to change them all to "private" users and let the new, rowdy guy in on a limited bases as a "registered" user, or to create a "limited" group that only has one person in it (currently) that is disallowed access to two forums?