If you're using the "Simple Animation Docklet" that comes with ObjectDock, you can't do much with it. It's only included as a sample for docklet creators.
However, if you download this Animated Shortcut Docklet
it will work for you. The only thing that doesn't work (at least for me) is the 'browse' button for the shortcut Path, and you'll have to enter the info manually.