Have you seen the "Indexes and Dictionaries" section under
http://www.mobipocket.com/dev/articl...Folder=prcgen?
You might be able to use XSLT to write a conversion, if you are good at XSLT (which is kind of a pain). Or, you might have to parse out the XML, then output the appropriate HTML for conversion. Perl has several goog XML parsers (I like XML::Twig).