"File and Printer sharing" firewall exception scope in Vista ?

Hi,
By default(al least in windows XP), "file and printer sharing" firewall
exception (those 4 ports I mean) scope was "local subnet". But sometimes I
need more - for example 2 subnets to access shares. It was easy in XP - I
could choose "change scope" button and do the job. But not in vista. "File
and printer sharing" firewall exception doesn't list those 4 ports anymore,
and of course there is no way to change scope.
How to change "File and Printer sharing" firewall exception scope in
windows Vista ??

thank you
Vilius