1) In Google Earth, save the selected path as a KML or KMZ file.
2) Go to http://www.gpsvisualizer.com/convert_input
3) Select Output format as Plain text.

4) Choose the file your created in Google Earth.
5) Set the Add DEM elevation data to: From best available source.
6) Press the Convert button.
It will create a text file the contains latitude, longitude, and altitude that you can copy and paste into your Excel program.

Hope this helps. -- Justin