forward question

[CT]

We have a public DNS in our DMZ

- Some of the servers in the DMZ provide certain services to services on 
the
inside.
- Currently, certain servers use the Internal AD DNS Servers for resolution
on a internal DNS domain to provide the services via firewall rules.

I would like all DMZ clients to use the Public DNS and "forward" the 
internal
DNS queries to the Internal AD DNS servers.

zone transfer to the Public DNS from Internal DNS is not an option..

*****************
zone "internal.zone" in {
         type forward;
         forwarders {
                 xxx.xxx.xxx.1;  // ad server 1
                 xxx.xxx.xxx.2; // ad server 2
                 };
};
*****************
Thx
CT