First off, tell your CIO he/she is a moron!
You cannot "add an Win2K file server to a NT 4.0 domain without joining the domain." That does not even make sense!
Explain to the CIO that you can add the Win2K server as a "member server" to the NT4 domain. This way, all NT user accounts will be able to access Win2K resources (providing you set up the security to do so). The server will then be visible to users in Network Neighborhood. All will be wonderful!
Once you are ready to switch to a new domain structure, explain to the CIO that it is easy to remove the Win2K server FROM the NT domain, and then promote the Win2K server to be a Domain Controller of its own domain WITHOUT HAVING TO REINSTALL WINDOWS.
My guess is that your CIO is afraid if you set the Win2K server as a part of the domain, that you would then have to reinstall the entire server (thereby losing all of the information on it) in order to set up a Windows 2000 Active Directory.
That is simply not true. Win2K Servers can be member servers, stand-alone servers, or Domain Controllers of Active Directory domains all while only having Windows installed one single time. It is not like the NT4 days, where if you made a BDC or a PDC, they were stuck being some type of controller unless you did a reinstall.
With Win2K, that limitation is gone.
I suggest explaining this to the CIO. Then tell him/her that it would be simple to add the Win2K box to the NT4 domain now for users to use.
Then, in Phase2, set it up tobe a DC in its own AD domain.
All done during lunch one Wednesday afternoon!
