Okay, you have a winmodem, you need to go check out
http://www.linmodems.org to see if they have drivers for yours.
About the shared internet, I am sure there is a way to do it, either by direct connection but that is way to much trouble for someone to do, it would be faster for you to just go out and buy a 20 dollar modem, especially with dial up connection, you would be in the stone ages on the internet connection setup that way.
