Migrating Exchange 5.5

I have a simple Windows 2000 network with two domain controllers. My exchange 5.5 mail server acts as a domain controller in addition to the other one. I am planning to create a single new domain using a brand new machine and load up Exchange 5.5 on that. The thing is that this new machine is not on the same physical network as my current machines. How do I go about transferring the user account information and the email accounts over to the new box??