Unified Messaging and Faxing

Hi:
Hope you can help!
We just configured unified messaging with Outlook. Our phone system is a Toshiba ES Stratagy System that allows faxing over DID lines. The problem is, the built in fax software is not very robust. I would like to use Microsoft fax, except that it wants me to install an actual modem. I want to use the Statagy ES Fax driver as the modem (printer) to send and receive faxes. Is there any way around having to install the modem?

Thanks!
Scott Sokolich