automating firewall changes in SP1

Hi,

When we rolled out Xp last year, we turned the firewall on. Now we
are rolling out managed Symantec Antivirus clients. To really manage
the clients well, the clients need to be able to communicate on udp
2967, which means opening a hole in the firewall. The problem is that
we don't want to have to go around to every machine in the building
and change the settings. We want to automate control of the firewall.

Has anyone come across a good, fast way of programmatically changing
the firewall in SP1? The netsh firewall command only works in ipv6
and the windows api calls are poorly documented.

Any good, existing scripts or quick answers?