A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
Well, at least my offering does not require you to change the filename extension from .GPX.
I didn't know if you were parsing each line as it is read from the file or if you were waiting until it was all entered, but assumed not until all was entered since using .OPEN would present you with a full sheet of information. So you should be able to use the code in place of a .Open statement.
One change you may want to make would be to put this statement somewhere ahead of the Do While loop start:
ThisWorkbook.Worksheets("Sheet1").Cells.ClearContents
change Sheet1 as needed. What it would do is erase any old information on that sheet before refilling it with current contents of the .GPX file. Note that it will always begin filling at row 2 even on a completely empty sheet.