Thanks, but clicking the file does get Excel to open it...but still in compatibility mode. I just can't pin it to the Excel icon on my taskbar.

Perhaps a better way would be to convert the files to the new format. Saving as .xlsx doesn't work, and the only advice I find is to go to File/Info and click the "convert" icon...which may appear in prior Excels, but not in 2016 as far as I can see.