Try Sportracks, the best program for your Garmin 705, Polar ect.
It is open source and there is 47 plugins.
http://www.zonefivesoftware.com/SportTracks/Forums/
also see:
http://www.zonefivesoftware.com/SportTracks/Downloads/?sid=63702b58322ce919b4b8523e6a27c55d
and:
http://www.sporttracks-plugins.de/SportTracksPlugins/MyPlugins/GPS2PowerTrack%20Plugin
