project help..pan and tilt

I am including a laser range finder in my project ,i am planning to mount it on a pan and tilt unit. And i need to point the sensor at an object automatically. am using a camera as well. i need the the pan and tilt unit to point the sensor at the object that i selected on the screen. what is the logic behind that and what kind of programming is to be done to achieve the same.
thank you

You will have a problem if the camera is not at the center of the pan and tilt. If the camera is off to one side you would need to know the distance to the object to figure out its coordinates in the pan/tilt view. That kind of defeats the purpose of pointing a laser rangefinder at it.