Server 10.3 PDC and Windows Clients

The question is how to go about adding other groups and user accounts to Windows clients. The X 10.3.2 PDC is up and running, we can create machine accounts, add machines, set Windows user preferences in WGM and all that just fine. But, when the machine joins the XDOMAIN it just picks up the group <XDOMAIN\Users> group. Attempts to add other groups or individual accounts results in an error on the Windows 2000 client that "there are no readable accounts on the server". Obviously, for this concept to be fully functional, we need to be able to create groups and user accounts on the server and be able to add them as needed to the client via "Add Users and Groups". Any ideas on how this can be done? Does the Open Directory schema on the X server need to be extended or mapped a particular way?