DOCBOOK: docbook XML

hi,
we here in Interra have work related to converting well-formed XMLs to
DOCbook XMLs. For every XML, we write a different set of stylesheets to
achieve our goal. we want to generalize this whole process, so that we dont
have to write stylesheets for every XML. 
is there any tool available for converting any well-formed XML to docbook
XML ? or are there any generic set of stylesheets for this purpose ?
may be i am posting this question at the wrong place, but i am desperate to
know. please reply to this mail. 
regards,
akash bohra