[Samba] joined to ads, mapped permissions

[Mike Partyka]

I have joined samba to a 2003 active directory server.

If a samba shared dir is owned by root, how does active directory manage it?

more specifically, how are the permissions mapped? administrator to root?

i have seen reference to a parameter in smb.conf to "username map",
but i don't see reference to it in either of the John Terpstra Samba 
books so that can't be the bridge between windows and linux
permisssions.

TIA