If you establish an Active Directory, you can achieve what you are looking for. I have RHEL systems that are members in a Windows 2003 server Active Directory. The Active Directory users can log directly into the RHEL systems with the same credentials that are managed by the Windows 2003 server. This also alows shares to go across the active directory as well, to specific AD users or groups.
Unfortunately, without the active directory I know of no way to keep them synced for you. Part of that password synchronization comes from the kerberos integration. Kerberos is required for the active directory setup.
Last edited by Passmossis; 11-07-2011 at 10:59 AM.