It is possible, however the support for nasty internal WinModems is a bit dodgey. winmodems are like floppies, they are cheaper than hardware chips, WinModems dont have all the parts normal ones do, they are emulated my software (
http://www.iac.es/galeria/eddie/linu.../winmodem.html). I had an LtWin modem and some champion had already created a manual and a set of scripts which configured and installed my model for me, have a search of
www.google.com/linux for your modem and see if anybody has done the same.