DNS design dilemma

I want to make a DNS server installed on a W2K DC a caching only server.
Problem; when DNS loads, it pulls the AD integrated zone and loads it. The advanced option ‘load zone from’ will not let me choose boot from file option because it finds AD integrated zones. The other two options load the AD zones.
Is it possible to have a caching only DNS server in this situation????????
We want our data center DCs to be AD integrated DNS servers, and our branch office DCs to be caching only DNS servers.
Any ideas are greatly appreciated.