<p>Is there an app that can change the order of images inside an icon?</p>

<p>Thanks!</p>

What you'll need to do that is a resource editor. A
google search
will reveal many free ones out there. The
restorator
is a great one, but not free and over-priced IMO.
Any decent resource editor will allow you to see icons in the exe or dll and save them or replace them. I don't know of any that will allow you to reorder them, but just about any out there would allow you to save the icons out and then replace them back in the exe/dll in whatever order you'd like.