I assume that your network card is what your cable modem is hooked up to to deliver your internet to your computer. Whatever USB or Ethernet port that your xbox is going into is the one that needs to be 192.168.0.2
I suggest a second NIC card devoted to xbox only, or get a router and you can set it up that way too. That is my current setup.
Try this: With your evox.ini file all configured and your crossover going into your NIC, go to the START menu...Run...type in WINIPCFG
select that NIC card from the drop down menu and then release all. Renew all and you might get 192.168.x.x