Add or remove icons from shell extensions in right click menu

Hi,

I was trying 2 days in a row to add some icons in the right click context menu. I was able to add some of them, for example next to "print" or "play". But I ouldn't find any way to add icons next to shell extensions, for example "7-zip". Is this any way via registry or via any other program to manage this ? I think that this is possible with Visual Studio, but I don't know much about it (but if it's possible a tutorial is appreciated). I have some experience with editing dlls via Resource Hacker e.t.c. Any help ?

P.S. : I have some screenshots attached, explaining what I want to do...

Thanks for the advice, but I don't have problems with the /shell folder. I had already managed to change the icons for this folder.
My problem is with the shell extensions (/shellex directory). Example : 7-zip shell extension in right-click context menu but no icon (that is what I want to add).

I believe that icons for shell extensions are controlled by the extension itself. I don't think you can control this.

I 've an idea about modifying the shellextension's dll (7z.dll). But how do I add the icon in the dll ?