Thanks everyone.

To let you know what I'm up to, check this thread:
http://www.kixtart.org/board/ultimatebb.php?ubb=get_topic;f=1;t=007920

In AD, you can right click on the computer and set the primary group in the same manner that you can set a users default group.

I have seen others ask for this feature, and will find the thread and post here. I did not see a solution posted.