GeePeeEx Editor is specifically designed to produce and edit GPX files destined for Garmin's® Automotive Satnav (GPSr) systems. These files can be used as input to Garmin's® POI Loader to produce enhanced Custom POI's (Points of Interest).
Geocoder is not working - again :-(
Yahoo have withdrawn their free Geocoding service (without any notice, of course). This time they are not offering any kind of replacement; at least not a free one.
It may be possible to switch to the Google Geocoding API, but it requires some investigative work, that I've not had a chance to do yet.
The bottom line is: at the time of writing, GeePeeEx Editor no longer has a Geocoding function.