I have the same one and it can be used, but it's complicated. First, go to google Earth and punch in the coordinates. Save that to your desktop. That will be saved as a .kmz file, so you'll need to download a converter program. (you can google that -- there's a couple of decent converters out there). After you've done that, use Garmin's POI loader to put the coordinates into your GPS and save as a favorite.
Phew!
I did it a couple times and it worked, but I'm going to invest in an eTrex, i think. Much simpler.