Slingshot like Angry Birds?

I have exactly same problem with ball shooting and showing line. Rickwhy you got it working? Could you tell me how? OR Matthew Prongle could you help me little bit? Problem with shooting ball and showing line is in touch coordinates and when group moves, coordinates are messed up.
Matthew Pringle could you explain this or show some code:

"would you need to transform between the touch x and y and the inner game group x and y when scaled and moved. This would be accomplished with a bit of sin / cos manipulation of the original coordinates and where they should be." 

I dont have any scale thing in my game, so could you post some code how to do that sin/cos manipulation,please? [import]uid: 18445 topic_id: 3277 reply_id: 40814[/import]