Best way of manage make a real world Shooting Simulator

Hi, I would like to make a Virtual Shooting Target Simulator. Project the screen with the targets at the wall of my house by a projector and purchase a plastic gun shooting Laser Led light. I manage to made the main menu and some target scenes in Unity3d.. Now i missed the way of what is the best-easy way of doing the reading of the laser led point comes out from the gun into the unity3d. I read you can manage do it with a webcamera opencv and unity3d but looks like very confused to me as a rookie. Is an other easy way to guide me..if it possible? Also i read that can be done by wiimote or playstation hardware.

Thank you