How to Reset the Light Source Position

Problem:

I have changed the position of the light source interactively using the mouse.
There’s no UI option to reset the light source to its original position.
How can I do this?

Solution:
Use a macro command to reset the light source position:

#!MC 1410
$!GLOBALTHREED
  LIGHTSOURCE
  {
    XYZDIRECTION
    {
      X = -0.2
      Y = -0.2
      Z = 0.959
    }
  }