I've collected many nice wall papers over years. 
I know python and c++ (a little MFC eperience).
I want to make a programme that can change my wallpapers.
I want to operate like this:
     there is a little icon (half transparent), if i click it, it change my wallpapers to the next picture in my wallpaper collection folder.
I found many infos of changing wallpaper by programme by google.
But can't find out the win7 API for adding a button on desktop.
Please some one tell me how to set a icon-button on the desktop, or it's just there's no such API?
EDIT:
    I just find that there are ways to make a window unmovable. So, I think now I need to find ways to make windows out of an icon. Then it'll looks like a button on desktop. And, there are ways to make windows taking some response when it's clicked(once), right?
Closure:
    Captain's method may be a better way for people with good understanding of windows. 
    I know python, but few knowledge of MFC or similar framework with deep relations with the OS itself. This desktop button creation is very hard to implement for me. 
    Modifying christian's script and a windows shortcut would be a not-good-looking compromise. I'll do it this way.
There is an easiest way.
Install VBest Icon groups. ( it is a desktop icon stack )
Then select any stack and add a single button. ( drag and drop any application will get its link and icon in the stack )
Select the stack and in its settings, set transparency equals 0 ( slide to left)
That is it. Now you have a single button with link.
create an button on desktop