wallpaper?

Is there any way to put wallpapers into the game, also, how do I change the overall appearance of the main menu?

All the pictures that game use are located at KHC/PPD/img (default folder is what you need). "wallpaper" is back.png
EDIT: you can download my "skin", to make it look like this
also other things may be found on PPD forum or PPD wiki page