For now, I'm 100% happy with my "workaround". Not much changed to the above approach, just this:
- Folder path changed to the more universal "%APPDATA%\Microsoft\Windows\Recent"
- Live Folder options: a) sort by modified date b) include documents, filter "*.xls* *.xlm*" (for Excel files)
- Added manual icons to my sub-menus; the (lnk)-document icons seem to correctly associated to e.g. Excel already!
Using the "*.xls*" including the "dot" now ensures that 99% of all found files are indeed only .xls* files.
Here's how it looks now, will test it under productive work conditions in the coming days.
"The looks" are great (for me) and it works as of now :-) ==> for other interested users, you might consider just adding this as an FAQ article? I think no real code changes are required... But let me check in the coming days, maybe it's not as perfect as I currently think it is. Live Folders are GREAT!! :-)
Note: I have LibreOffice installed here, that's why the "Word" icons look a little bit unusual, that's the LibreOffce icon (although looking a little bit differently). At least for pdf, I do see the "real" pdf icon. Will test on another machine running MS Office in the coming days.