Just a comment on why this manual conversion is even necessary: Ideally, GE would simply import a GPS tracklog file (converted to .gpx with G7to win or directly from the GPS) and create a Path placemark, all in one move. But, at present (general release beta), GE has some problems. I've found that trying the above strips the altitude info. And you only get individual points instead of a path.
I've also found that when I try to fly a path (tour), the camera goes along the ground instead of at the path's altitude.
I expect that the GE team wil get these bugs squashed, then you won't have to deal with gpsbabel or excel any more.