These settings may work with all HTC phones, But here they are specially mentioned for HTC TyTN 2. Please also note, not all softwares will work on HTC hardware, for any such software, contact its vendor. Here are some settings for generic softwares.
1. Tap on Start > Settings > System tab to select the External GPS.
2. In the Programs tab, Choose and set the GPS program port to COM4 port.
3. Now In the Hardware tab, set the GPS hardware port to (None) and choose the Baud rate to 4800.
4. In the Access tab, you make sure that Manage GPS automatically is selected.