Change Bluetooth Virtual Port Number

I have a Dell Wireless 350 Bluetooth Internal card installed in a Latitude Dell D610 running Windows XP.  The card is running under the newest Bluetooth software driver, recently downloaded from your web site.  The Bluetooth software and card work fine with other hardware components.  When it establishes a connection with a Pharos Bluetooth GPS, it assigns it a virtual port number of either 40 or 42.  I am attempting to use the GPS device with Microsoft Streets & Trips.  Devices assigned to COM ports above 20 are not recognized as GPS devices by Streets & Trips.  I have been unable to reassign or change the virtual serial port number.  How can I reassign these asigned vlaues to a lower value?