Hmm, I think I have another idea:
After you're done with it, search for Microsoft PPS Viewer on the internet and download it.
In the end type
winecfg # A window will open. In there you might select XP as emulated os. Or leave it on 2000. Don't think it'll matter for now. Press OK to close it.
wine name-of-the-file.exe # And Click next...Finish
Then try opening a file with this program, which should
be found in Applications-Wine folder.