LightMatcher is a 3ds Max script by Martin Breidt that exactly matches a Free Spot light to a camera. The alignment is precise, so the Free Spot ends up positioned to correspond with the camera it is matched to.
The script is intended for cases where projector lights stand in for camera mapping. In that setup, a Free Spot needs to line up with a camera, and LightMatcher performs that match directly. Version 1.2.1 is the current release, which fixes some bugs from earlier builds.
LightMatcher is listed here as free and is distributed through Martin Breidt's collection of 3ds Max scripts on his own site. For the download, current licensing terms and any setup notes, visit the developer's page. It also appears in the ScriptSpot library alongside other 3ds Max tools from the same author.