filter "unwanted" DNS queries..how??

[magiciq_pop3.concepts.nl]

Hi,

Our DNS is not connected to the internet, it is connected to a private 
network.
We are facing a problem. In our DNS we get a lot of "unwanted" queries. To 
answer they it

costs our DNS CPU time/load. I want to avoid that.

I have a list of domains/zones that my DNS will resolved them, the rest 
outside my list

will not be resolved
The question is how can I block those queries, in the named.conf --> option 
maybe?? But I

dont't know how..

E.g. domains:
mnc001.mcc001
mnc001.mcc002
mnc001.mcc003 are allowed.

rest domains like:
mnc003.mcc040
mnc020.mcc005
mnc001.mcc262..etc..etc..I want to block them.

Please let me know,

Thanks