BuddyPress.org

Hi all,
Does anyone know how to create a permanent private circle group for all users. In other words instead of users creating groups, I want to create 1 or more groups for the users permanently and have control over the member type(s) that will be the admin, however I will choose the number of people that will be in that circle it could be 3 to 100 not sure, but I want to control the limit and give the user specific guidelines as to what they can do. Could you direct me as to how I would go about doing this with WordPress?