Hi shell,
1) I searched for admin_share as per your post and found a very useful template expansion, which I'm now using. This is absolutely most useful in a school environment

2) Thanks for the pointers to LAT. I've read their man entries and did create users as per -i /path_to_file method.
I should have been clearer on that point:
I have a group name in the correct position, and the users were correctly assigned to that group.
What prompted my post was desire to assign primary GID's, (from a file), on user creation. LAT, (and SME panel), assign the user name as primary GID, no matter what other GID's are specified.
I can show the school how to change this using WinSCP - for e.g if a teacher
was just interested to know if anyone has come across this "requirement" and if they had a "solution"
BTW, this snippet is from an Ubuntu + Samba setup, and works by allowing access to certain groups only:
[users]
create mask = 0770
comment = User Admin
valid users = @group1, @group2,@group3
path = /home
write list = @group1, @group2
browsable = yes
I wonder if that can be used on SME Server? - don't see why not.