The question “How do I retrieve a Command from a CommandBarControl?” has been posted in the forums at least a couple of times and my answer always was “It’s not possible” because the CommandBarControl lacks a Command property, which is the intuitive thing that one would think. It was not until today that I realized that MS provided a way, although far from intuitive:
HOWTO: Retrieve the Command that created a CommandBarControl from a Visual Studio add-in or macro
http://www.mztools.com/articles/2008/MZ2008021.aspx