It looks like gpx is a standard XML schema based format, can be read directly by most anything these days without writing your own parser or resorting to perl
for this excel example I had a gpx file at c:\tmp.gpx (actually I just saved
http://www.topografix.com/fells_loop.gpx since I don't have a gps)
I went into Excel
then hit:
Data->Import External Data->New Web Query
Then for address I put in the location of the gpx file:
file:///C:/tmp.gpx
And then I was looking at tons of data
I had to scroll right to see the parts that change since it is expanded to rows.
fyi, using excel 2002