[Powlo]

The way i would do it (but probably not the easiest) is to change the name of 'Registered Users' to New Members.

Then set up a new group called 'Registered Members'

You can then set up a Promotion Strategy so that your new members will be promoted to 'Reg Members ' after x days or whatever your criteria will be.

AdminCP -> Usergroups -> Promotions

Sounds a bit long winded and im sure it is but it will still work.