Solved after writing this:

I tried your suggestion. I went to the Programs folder, found Winword.exe, pinned a shortcut to the Start menu. "None" remain un-editable.

The target is "C:\Program Files (x86)\Microsoft Office\Office14\WINWORD.EXE"

Start in now says "C:\Program Files (x86)\Microsoft Office\Office14"

What am I doing wrong here?

Solution: Though None remain un-editable, simply pressing the desired shortcut-key sequence replaces it.