In page 8 of the Reality XP GNS WASS User´s Guide.pdf says:
8 - Export Flight Plan: Using the right mouse button on the click spot exports the active flight plan in a Flight Simulator compatible file. The flight plan filename contains the UTC date and time and is saved in the following folders:
FS9:“My Documents\Flight Simulator Files”
FSX:“My Documents\Flight Simulator X Files”
NB: it can take up to 5 seconds between a flight plan changes and the file saves. An audible warns when the file is actually saved.
Flight Simulator is only capable of loading a flight plan file which starts and finishes with an “airport” waypoint type. As such, the GNS WAAS 430XP/530XP exported flight plan overrides the first and last waypoint type to “airport”. This permits creating the flight plan on the GNS, exporting it to a file and then loading it with Flight Simulator for proper ATC operations.