[Graphics] Pokemon Platinum - Changing pokemon sprite shadows

I was able to figure out how to edit pokemon animations and pokemon y-offsets, but I don't know where to find anything regarding the shadows that apear under Pokemon. Editing poke_shadow.narc doesnt do anything. Could the information be in an Overlay? I looked through the files and couldnt find anything else. I hope someone can help.

I tagged a screenshot incase it isn't clear what I want. The shadow under the pokemon is medium sized. I want to change it to the small size.