Moving Player Object in 3D Space on Tap

Hi Everyone! We have been pounding our heads around trying to get our Player Object to move in 3D space when you tap on the screen (iOS). We have a camera that tracks you (keeping the player centered) using an orthographic camera. We've been trying Raycasting, ScreenPointToWorld, etc, with not much luck. :( Made a video to better describe visually what we are trying to do: http://youtu.be/AnbNvbnHK-g Sorry if I stumble around in the video. After two days my head is a little fried from trying to figure this out! Any advice to get us going in the right direction again would be incredibly helpful! Thank you!