how to override only a single 3rd level domain on local dns server

Situation:
My company's isp has a weird setup. They give us no public ips and forward ports from their external routers to our servers if we need. Moreover, they do not allow connection to the above mentioned public ips from local network.

We have a site running at an address, for example fake.mine.nu (registered thru dyndns.org, so we dont own mine.nu).
So, if i use isp's dns from LAN, fake.mine.nu resolves to their external ip which i cant access.
I have a win2k3 domain (and dns server), so I want to override just this one third level domain to return the private ip of the destination server, and let everything else be resolved by upstream dns servers(i just create a primary zone mine.nu and add host "fake" to it, but then anyother.mine.nu will not resolve).

This is similar to setting up a hosts file on the client, which, of course, is not an option.

Interestingly enough this used to work, because our isp had some special setup that would return the private ip if the returned name was in their list of routers(or someth like that).
So this can be done. I just cant figure out how on windows dns server.
Thanks!

create the fake.mine.nu primary zone. There's nothing that says anything.at.any.domain.depth.com can't be a zone.

Sun of a gun!
I didnt think of that!

Thanks for the prompt reply!
I removed the NS record for this zone. This doesnt matter right? Cuz there is not gonna be foo.fake.mine.nu.

Thanks again.

NS records are required by BIND. Don't know about Microsoft DNS Server. One NS record referring to the local server would be considered the *right* way to do things.

Thanks again!