can i create a modem from my 6700 to my pc to my xbox 360?

[drunkdirtbiker]

i was able to use my 6700 as a modem for my computer, have my computer run at 921 kb/s from my fone, and i both running on the dns servers 208.67.222.222 and 208.67.220.220. now i want to exeed those limits and try to get my xbox 360 running off of my fone to my pc to my 360. so far i have my fone and pc connected, my pc is connected to a linksys wirless-g broadband router and that is connected to my 360, but everytime i test my connection on my 360 i get: network adapter wired and
ip adress confirmed, but when it goes to check for dns it fails.

if you guys know any way to do this i would be extremely thankful

P.S. sorry for the repetition, im not to good with explaining things