The answer is far too long to fit.
Read articles like http://www.engadget.com/2005/01/18/how-to-use-your-cdma-cellphone-as-a-usb-modem/ and get a compatible phone.
I am trying to use my cell phone as an analog line to dial in to a modem to work on PBX systems. I could not find any help with Verison's web site. I have a pn-820 phone and windows XP.