[wlug] iptables question

This has more then likely been asked by a million people with a million different answers but here goes. I was wondering if it is possible for iptables to filter by a domain name? I would like to restrict port 80 connects to .nz domains only and all others are stealthed. The solution does not need to be very fast, handle more then one high level domain or any other ports and is not for commercial usage. Any solutions?