I am keen to hear from anyone who can help me.

I am creating a aerial perspective to scale of film sets used in studios or locations.
Within this I drag and drop in lights and sets from stencils, using the scaling mechanism.
Given that any specific light outputs a known amounts of light that falls off using a inverse square law I was wanting to enable a "light" from the stencil to possess these values. So that when I drop it into a set and I drag it to a point it automatically give me a value at that distance.

So to give a example.
If I had a bedroom set within a studio I could then drop in a light in my sketched diagram. Lets say a 2K, and point it through a window towards someone sitting on the bed. If that light is at a distance of 5 meters from the seated person I want OG to to use the distance and apply the inverse square law to calculate the value at that distance.

So to explain further.
I am fairly certain there are two ways to do this.
The first would be with a Action.
Within Properties:Geometry the X and Y coordinates are given of the location of any object that is dropped in.
I have enabled the scale.
Then within Properties: Action I want to have "clicking with the Browse Tool: Runs a script." So that when I click on the runs script button it would run this calculation.

The second and easier way would be by drawing a line from the light to the object with the Edit/Insert Variable/Line Length function.
I understand how to do this but have not worked out how to get this line length to perform a calculation. So that rather than display the length of the line that it might use these values to perform a calculation.

I am most interested to hear any suggestions.
Thankyou. Adrian.