DOCBOOK: Upcast to Docbook?

Hi there

Has anyone done any work on stylesheets to transform the XML results for 
the RTF to XML converter called Upcast?

Upcast seems to create a better XML structure from my Word docs than (say) 
Logictran & Majix has but it has it's own Generic DTD - I'd rather not 
re-invent the wheel if possible.

TIA.

Mart