Move to another forum if necessary.
Hello there. I already know that there is a .ico file format plugin. Even though i'm running a Windows machine, I still have lots of ICNS files floating around when I got some icons from Office 2011 for Mac. Though, the only problem is that, as soon as I try to open it, it gives an error: The image type is not recognized, and cannot be opened. If someone could make a plugin for this, then that would help a bunch.
EDIT: This is pretty much useless now. Simply get XnShell and convert ICNS to ICO then use the ICO file format plugin to use that.