I'm a little confused. If you have a router why do you need 2 nics? You run your pc nic to the router, and you run the xbox nic to the router.
Further, you pretty much answered your own question about how to set up the addressing for the 2nd nic (in your router-less scenario)... you listed the IP and mask for evox, just choose a different address (192.168.0.2, for example) for your nic.