I have a similar request, though in my case it’s on the desktop.
I already tried the Commander plugin, which allowed me to add the “Calendar:Open View” command from the Calendar plugin.
However the new command doesn’t work. I guess this is because the Commander plugin gave me a warning: “This is a checked Command, meaning it might not run under every circumstance.”
So now I’m wondering, why do some commands automatically appear in the Ribbon while some can’t even be forced into it? Could anyone point me to where can I learn more about this, so that I can find where to file a bug or try to come up with some fix?