maxscript access to multi environment maps

[regulus]

Hi, does anyone can show me how to access the number of maps in corona multi environment maps dropdown list inside render elements CShading_LightSelect?
I prefer the array values in the bottom.



I've been looking for hours without result.

Also I'm curious about CShading_LightSelect "nodeSource" property. What is it?
Print only get value of "0" (zero).
Thanks in advance for any help.

-- edit:

It turn out I was looking in wrong places. Its simply:

renderers.current.bg_mapCount
renderers.current.bg_texmapList

Still dont get nodeSource though.
Cheers everyone