Is it possible to launch a Powerpoint Show (PPSX) with Articulate?

Hello Heroes and everyone else,

I need to  launch a Powerpoint Show presentation (PPSX... not PPTX) by clicking on an object in my Articulate project in a local environment ( i.e. by launching Launch_Story.exe)

Anyone knows how to do this ? Just putting the the full path with filename in the hyperlink does not work on my machine, Should it?

The only way I managed to do this is indirectly, i.e. a hyperlink from Articulate to an HTML page that has links to my PPSX file.

I know this is awkward, but everything else I tried (e.g. Javascript) failed.

That created another issue:

The link is opened in IE ( and my default browser is Firefox!) and IE doesn't launch the PPSX  viewer  (full screen) but launches Powerpoint.exe.

So... does  anyone know how to set Articulate to open locally Firefox and not IE?

Thank you in advance!

Vanyxa