Thanks sweetasman01 and spwolfx for your helpful answers.
DirectSkin from Stardock is the most popular engine for adding skinning technology to an application and is used by software developers. It is used by some of the biggest companies in the world, including ATI's Catalyst Control Center, Reuters, BellSouth, General Electric and more. But you have to be a programmer to use it.
But because it is based on WindowBlinds technology, WindowBlinds skins can be easily adapted. PowerArchiver presented instructions on exactly what is needed.
Thanks again for the posts.