TCP/IP Readdressing & DHCP Server

I'm not sure what you mean by "Each DHCP Server is set up with the server address coded into it". And there are no short-cuts that I know of to creating DHCP scopes.

Here's how I would do it: First, multi-home the DHCP server. Basically, that means you add a 2nd IP address to the NIC. Now the DHCP server can talk on both the new addressing scheme and the old. Next, multi-home all the router interfaces and wait for the routing protocols to do their thing (replicate to all other routers). If you've done your job right, you can now move all your servers to the new IP addressing scheme. Double-check WINS and DNS as you move the servers to make sure the old addresses are being replaced with the new ones and changes are being replicated to all WINS & DNS servers. Once that's done, start rolling your workstation subnets one at a time, creating the DHCP scopes as you go. After you have all the subnets moved over, you remove the old IP addresses from the router interfaces and the DHCPserver.

You should search for info about DHCP Relay Agent

We obtained from Microsoft a White Paper that gave us a guide for this change.

As long as we followed an exact series of steps to change the IP address of the server, the DHCP Manager would automatically change the registration IP address it had to the new address.