Create a spot light, set 2 Views, one for active camera, one for the extra camera
Create an extra camera, name as Light View
AA open both Light View and Spot Light layers→
In spot light, hold Alt on stopwatches of point of interest and position,
drag the parent link icon to the interest and position on Light view layers respectively
Activate the camera cotnrol (C), now the Light view camera move with the Spot light together, so it controls the light much easier