Malibu,
I have tried and could not do it. I went to
www.pocketpcthemes.com and found this in their FAQ section:
"I have downloaded a couple of your themes, but they don't seem to work on my Jornada 54x, Casio E-125, etc. How do I get them to work with my older device? The concept of a "PocketPC Theme" is new to Microsoft's PocketPC 2002 operating system which was released on October 4, 2001. If you own an older Pocket PC device, you can purchase a product from Novosec called Pocket Facelift which will allow you to run themes from my site."
So the answer is no!