[Samba] group policies in samba PDC for windows 2000 professional and xp clients

[saad khan]

I have configured a samba PDC with windows 2000 professional and xp clients
and the PDC working fine, but how can i implement group policies for clients?
like i want to disable run command from start menu or i want to allow
a group to use msn and other groups shouldn't able to use msn.
how can i implement these group policies object in samba PDC?