I thought what you wanted was a program that could handle both Voice and Fax when the computer is used to handle incoming phone calls.

What you want is a device that will be able to send a fax phone ring to the fax machine but sends the voice phone ring onto your phone so that you can answer it.

If you check with a phone/electronics store or with an office supply store, you should be able to get what you want. My old accountant had one of those things that could separate them out.

Good luck and post back if you find it.

Doc