Is there a way to add a group handle to a tool?

I have an animated cannon and I'm trying to add it to a tool. All the parts are in a group and bound along with a custom animation that works fine outside of the tool. Whenever I add the group it too the tool, the animation stops. Also, even when I name the group "Handle" or I name one the group's parts "Handle" it still doesn't work.

So basically this is two questions in one. How do I add a group as a handle to a tool and how do I animate a group in a tool. I know this is tricky, but I'm really stuck right now so any help would be much appreciated.