Edit commands

Our application has an edit menu similar to that found in the DiagramBuilder application. There are cases where we do not want to allow the user to cut/copy/paste/redo/undo and thus we are attempting to disable those menu items. However, the user can still select nodes on the diagram. I found that I could override CanPaste and CanCopy in the DiagramController. However, CanRedo, CanUndo and CanCut are not overridable properties. I know that I can still disable the actual undo/redo/cut but overriding the Undo/Redo/Cut methods but it would still be nice to have those menu items disabled. Is there some easy way to do this that I might be missing. Thanks in advance for your help. Chris C.