how to add background image on the left side (where is the library)

I am developing a theme from the life is strange game, because I noticed I did not see any theme from this game for windows 7.



I want to put an image in the white space shown in the image, i use windows style builder, the path i know is explorer & shell / explorer / propertree

In my case mine is like this:



I want to know which properties should I put, and everything else.
In short what do I need to do to have an image there? it is possible ?

I asked someone if they would help you with this. Don't know if it will happen.