send NXDOMAIN to ISP DNS server?

[BLZ]

Hello. I have a LAN with a DNS server to keep track of the lan
computer's names (
   h1.home.net   192.168.0.1,
   h2.home.net   192.168.0.2,
   ...
 that sorta thing.)

I have a very simple setup:

options {
 directory "/etc";
 pid-file "/var/run/named/named.pid";
 };


zone "." {
 type master;
 file "/etc/LAN.hosts";
 };


zone "0.168.192.in-addr.arpa" {
 type master;
 file "/etc/LAN.rhosts";
 };

How can I have any random NXDOMAIN (non existant) domain, i.e.
yahoo.com, be passed on to the isp's dns server to resolve the millions
of domain names my local dns server could not possibly know about.

Right if I go through nslookup I cna only resolve local names and ip's
using the lan dns server.

Thanks.