We had the same issue in our group - we wanted a small, "administrators" group for private conversation. As Duane said, you CAN make this a subgroup, but we elected to have a separate (free) group for this purpose because we felt it was too likely that, being a subgroup *in the same domain*, we might inadvertently send a private message to the whole group! This way we are totally separate and pretty confident we won't mix them up. Our main group is a Premium one, but since there are only 7 people in the Admin group, and we don't need a large amount of file space, that one was set up as a Free group so it did not add to the cost.
Just sharing what our group did for this (and why). I realize we all have different needs and so this might not be best for you.
Barb
