Opening an Excel worksheet on the IFS...

Hi All, I'm using RDp 8.5.1.
I expand the IFS directory and get to a spreadsheet I want to open. The
icon displayed to the left of the name is the Excel icon.
I right click and Open With and the options are Text Editor, System
Editor, Default Editor and Other... I then select Other... and a window
pops up with all the file associations on my PC. (At least I think that's
what I see). I can then scroll down to Microsoft Excel Worksheet and
select it and the worksheet does correctly open in Excel.

I looked in preferences but I could not find how to either set a default
application for opening type .xls nor could I find a way to change the
context menu and add Excel to the Open With dialog.

Does anyone know how this can be done? As I said it does currently work
but I have to go through more steps than I wish.

Thanks,

Robert Rogerson