wmi filter for a subnet

i am trying to apply a gp on a subnet

I tried this

Select * FROM Win32_IP4RouteTable
WHERE ((Mask='255.255.255.255' AND NextHop='127.0.0.1')
AND (Destination Like '10.1.7.%'))

and this

Select * FROM Win32_IP4RouteTable WHERE ((Mask='0.0.0.0' AND NextHop LIKE '10.1.7.%'))

and this

 SELECT * FROM Win32_IP4RouteTable WHERE Mask = "255.255.255.255" AND Caption LIKE "10.1.7.%"

no of them work I even tried this

http://technet.microsoft.com/en-us/library/cc738954(v=WS.10).aspx

so I can link It to a site but when I right click on the site - properties

no group policy tab man

:(