Firewall control via command line / gpo / rules export

I have 2 x 3 pack of NIS 18.5.0.125 bought before any centralised administration tools. Is there any way I can automatically have the same configuration for them all. The machines are Windows XP to Windows 7 and are configured and in use so imaging them isn't an option. So are any of the following options possible, and if so how?

1) Export the firewall configuration from one machine and import to the rest

2) Script firewall changes (I have admin rights)

3) Control through GPO (the machines are joined to a windows 2008 domain)

Regards

Chris