Groove Agent and dragging complete hitpoint track?

I watched this video: http://www.youtube.com/watch?v=VbmvvkN2B7M

I can drag individual tracks onto the various pads and the pads will play them, sure. However, in this video the author makes hitpoints on a vocal track and then drags the whole thing, all the parts together, onto the lower left pad of GA - and then the hits are spread around to all the pads. How do you do this?