Can I automatically ROUTE ADD xxxx after i make a VPN connection in Windows 7?

If you have multiple VPNs you might run into the issue that when they connect in random order, their interface IDs change. In that case the normal ROUTE -P ADD 10.0.0.0 MASK 255.255.0.0 10.0.0.1 IF 42 does not work. The next time the VPN connects it might have a different interface number.

Powershell has a cmdlet available that adds routes on VPN connection and removes them again when the VPN is disconnected: Add-VpnConnectionRoute. It works without having to specify the interface ID.

The basic syntax is like this:

Add-VpnConnectionRoute -ConnectionName "VPN Connection Name" -DestinationPrefix 10.0.0.0/16

After entering this command, the routes will be created/removed automatically on connection/disconnection of the VPN.

If you want to make it a 1-step process, you could create a batch file that runs rasdial to automate your VPN connection and then does a ROUTE ADD:

rasdial "connection name" username password ('*' to prompt for password)
ROUTE ADD 10.1.0.0 255.255.0.0 172.16.3.0 

This assumes you're connecting to a Microsoft VPN, but you could script the OpenVPN client in the same way:

openvpn c:\path\to\config-file.ovpn
ROUTE ADD 10.1.0.0 255.255.0.0 172.16.3.0 

netsh interface ipv4 add route [destination/prefixlength] "[interface/connection name]"

I'm using that to deal with connections that have subnet overlap by adding static routes for hosts on the remote subnet - servers and the like.