2 DNS entries for same server

i have a 2003 DC file server that also doubles as an intranet server.

Nic 1 is confgured in DNS for the clients to connect to the shares using the server name, but i want to make NIC 2 hold a different DNS name for the intranet.

The problem is, is that DNS keeps recreating a DNS record for the 2nd NIC using the server name, which the clients then pickup and shows the server name in the browser and not the friendly intranet name.

i thought of using a cname record and only 1 NIC, but not so sure if that is the correct way of doing this.