Hasta La Motion!

I would like to create new layer with one still made as average of pixel value for all comp.
I guess there could be script to do this or maybe someone knows very similar script I could use for the purpose.

so, if there would be only 10 frames, it would take the intensity of all pixels, average all of (1,1) pixels in all 10 frames and use this RGB value for (1,1) pixel of this new still layer.

I can’t really imagine, who would ever need this kind of function, except me, but never know…. And I need to do it for comps with hundreds frames, ideally quite automatically.

Thanks!