Hi I would like to get some advice on how to possibly set this scenario up and the best practices.

Scenario:

There is an AD domain, which maintains the Exchange server, and other campus systems. I have my own NT4 domain outside of the AD, which I am trying to retire(the server, not the domain). I would like to use my RH4 box to become my domain controller, however I would like to use the AD domain to authenticate my users. They currently have an account on the AD side and my side, and would like to get out of the business of user accounts if possible, and to also allow for single login passwords. I want my DC to run my users login scripts, and if I can keep from it I dont want to put any of my machines into the AD if at all possible. I have read the tutorials on migrating and using vampire, done it, just not exactly what I want. Can someone point me in the right direction? TIA.