I know that adobe Fireworks is for the web, and not for printing, so exporting with CMYK is not an option...

The answer me this: Why is there a PRINT option in Fireworks?

I designed a book jacket for my new book, and the printer wants the color in CMYK, not RGB. It's causing me all kinds of headaches, even though the book jacket looks absolutely amazing when I print it out at 300dpi on my new HP printer on 8.5x11 high glossy photo paper.