The primary hint is I think "netsh" as that is the main tool to do tricky network things, but I don't think any variant of Windows supports source based routing (but I can quite well be very wrong there). Likely the easiest way is to route a more specific prefix where the PoP etc lies in over the correct interface. eg: route add 192.0.2.0 mask 255.255.255.0 192.168.0.1 metric 2 Where 192.0.2.0/24 is the prefix where the PoP lies in and 192.168.0.1 is the gateway that you want to route your traffic over. See amongst others: Microsoft: XP - To add a static IP route

Yes, as that is where your packets go and by adding that more specific route it will go over the interface requested (and the source address will be properly chosen too etc).