Hmmm, I was hoping it wasn't. I found a tool on the Russian website where Book Designer is found called Win unIMP and got my hopes up. It appears to deconstruct the IMP's into to a resource directory, but I can't make anything out of the results. I checked the web looking for more details, but all I found were technical specs of the directory's contents; nothing that I saw was leading me in the right direction. I guess my only alternative is to convert it to PDF using the eBook Viewer and resize to Reader specs. I'm sure there has to be a way to get the stuff out of there is a piece of software on your PC can display it for you (it even lets you select words/paragraphs/etc.).
Thanks for the input!