Unfortunately the USB GPS20x only sends proprietary Garmin GPS data. To use it with other mapping programs such as S&T you would have to purchase GPS Gate.
http://franson.com/gpsgate/
That program can read Garmin data and translate it to the standard NMEA format used by other mapping programs.
It will also allow you to run more than one GPS program at the same time on your laptop. The shortcoming of GPS Gate is that, as of this time, Mobile PC will not recognize the COM ports it creates.
Terry