how to change the default usergroup that new users are put into?
 

Right now, I moderate all new members, and they go into registered users automatically. I would like to change to so they go into a custom user group that cannot send PM's. I created the new usergroup and understand how to promote them from the new usergroup to registered users. What I can't figure out is how to automatically drop them into this newly created usergroup after approving their registrations. Thanks in advance for any help.