Domain Controller issue

We are relocating to a new facility and need to build a small network temporarily in the new building. In order to have all the user data and the same domain name in the test environment we need to add a domain controller to our existing network, then disconnect. This server will be our DNS/DC server. We will also be bringing online other servers such as SQL, SNA and a file/print server. How can I make this server a “primary” after it is disconnected? The Global catalog will not be on thisserver, what impact will this have? When I bring the original domain controllers on to the network what impact will it have with the servers and the workstations? Can I back up the System state and restore this to the server without ?adding? it tothe existing domain? Is there an easier way to do this?