adding Domain TO nt4 server

I have a PDC BDC server that has a remote domain I do not have a local that i can log onto ifthe remote server has a problem how can I add a local domain with out screwing with the PDC domain settings,, I need to be able to access the NT box if heremote server can not authenticate the users,, Right now theonly person that can log onto the BDC server is the actual ADMINSTRATOR users can not log into it even if they have admin rights any clues on how to add the local DOMAIN to the local server ??