What this reminds me of, is like when you have an empty project in a visual IDE, and you just build the window and the menu parts, but don't have any commands associated with the UI elements yet.
Perhaps the product could be exactly that; an empty (command-less) window with menubar, but the menubar content gets populated according to a plain text config file.
XML would work very well for this, but CSV would be easier to deal with, I agree.