If you want to sense a specific point from far away rather than a wide area:
The motion sensor normally senses motion in 240 degrees. You can make the degrees narrower by covering up two sides of the sensor. It seemed to work best by leaving a one inch space about 30 degrees off from the center led on the sensor. I tested it out from 30 feet away (9 meters) and it would only activate in a 2 foot area (.6 meters). It should work as well at farther distances.
You could mount it on a servo and have it sweep an area. It's activated by a change in IR light, like from body heat, so you could identify where someone is in a large room and activate this light rather than that light, etc.