VPN Split Tunnel Setup

Dear all,
I am trying setup a split tunnel for our VPN - accessing the Internet
via my 8Mbps Comcast cable, while accessing the Intranet via the VPN
connection. Under Windows XP everything was working fine, one Windows
Vista the split tunnel script I had is not working anymore.

The old script looked in 'ipconfig' for 192.168.48.* (our VPN subnet),
and determined my IP address on the VPN. The subsequent commands
were
route delete 0.0.0.0 mask 0.0.0.0 <myVPNIPAddress>
route add 172.16.0.0 mask 255.255.0.0 <myVPNIPAddress>
route add 192.168.47.0 mask 255.255.255.0 <myVPNIPAddress>