I have setup the win2k3(standard version)  box with active directory
and dns.(domain controller)
Brief Description:
ns1.mycompany.com with ip 192.168.1.10. this box is the domain
controller ,name server and also the web server hosting the websites
mycompany.com and mycompany1.com
192.168.1.10 has the network address translation to the public ip
207.X.X.X thru checkpoint firewall. the rule is setup at checkpoint
firewall to allow http (port80), tcp and udp 53 for name server
queries
But when some one queries the name server ns1.mycompany.com , the name
server returns the private ip 192.168.1.10 instead of 207.X.X.X.
we have to have ns1.mycompany.com as the primary name server for the
website mycompany.com
Please suggest me the exact steps for
1.active directory and dns configuration and 
2.what else needs to be done at checkpoint firewall