Network & Sharing Center - How Do You Add Network Icons

I want to add additional icons to the 'system32\pnidui.dll' file. That's where you pick which icon you want to represent the active named network in the Network And Sharing Center. I did a search in this forum on 'network icons' but didn't find anything. Aside from all the permissions restrictions what app can be used and what kind(s) of files will work in W7? I have lots of .png images that I would like to use if they will work. Lenovo T500 W7 Pro-64 Current Updates. TIA for any help on this.
Bob Helms

I figured it out, one of them DUH! experiences. Just look for the new icon where ever it lives using Browse and then add it. No need to add anything to pnidui.dll.