Join Request to Primary Usergroup

[TriMe]

I've setup the joinable moderated usergroup. My question is, is it possible to move that user to the usergroup as a primary member. As it's setup now, the user is added as a 'additional' member instead of a 'primary' one.

The reason I want this is for privacy. A user moves to a group that isn't displayed on the member list. I want registered members to be on the list, and members can apply through a group to be taken off through group memberships.

Thanks,

TriMe