> I want to break it into 5 files for punctuation&numbers, a-f, 
> g-l, m-r, and s-z.  

Part of the solution might be to use a grouping key created using

translate(., 'abcdefghijklmnopqrstuvwxyz', 'aaaaaaggggggmmmmmmssssssss')

Michael Kay
http://www.saxonica.com/