Setting Up DNS Server

We need to configure a simple DNS server to resolve our internally hosted domains to local server IP addresses whenever a workstation on the local network attempts to visit one of our domains. Scenario: We have 30 domains forwarded by our ISP to the IP address 162.39.22.25 . This global address is mapped by our Cisco 827H router to local address 10.1.1.2 . Right now, anyone outside of our local network can get to our site successfully, but all machines on the local network cannot get to the site through a web browser using a domain name. It was suggested by the Cisco support staff to create an internal DNS server specific to our domains so that they are resolved to the local IP address rather than the global one. All other DNS lookups would hit the secondary DNS server, which is our ISP's, and therefore be processed to a global address and work properly. DNS is installed on a local Windows 2000 server, but we do not know how to properly configure it.

Thanks to anyone who might be able to help me.

You say DNS is installed but I don't know what brand it is. If it is Microsoft's DNS Server then somebody else will have to help you. If it is BIND then you can probably figure it out from the example below:

http://serialcoders.sytes.net/BIND/named.conf
http://serialcoders.sytes.net/BIND/example.com.zone

My LAN setup is such that all computers are configured to use my dns server. The dns server is authoritative for the domain "example.com" and the server will resolve all requests for that domain locally. All other requests are "forwarded" to my ISP's dns servers.