Creating a temporary domain

When migrating from NT 4 server to 2000 server our former systems admin failed to demote the NT PDC before killing it resulting in a currently corrupt forest. I have searched for a final backup from the NT server to recreate the domain and demote the PDC but none exists, I am unable to promote a BDC because my system is still looking for for the former NT PDC. Will creating a temporary domain solve this and how would I create this domain and join my exchange server to it while I take what should be my PDC down and rebuild it. Also I have done very little research as of now into .Net Server does anyone know if upgrading to .Net server will allow me to fix this problem without rebuilding my domain.