DOCBOOK: Resend: A single multi-lingual documet -> multiple translatedoutput files?

Excuse me, I'd sent a unfinished e-mail by error. Here's my question.

I am a part of a software/documentation localization effort, and am interested 

in using DocBook to manage translations of our documentation.

The currently available transform processors for DocBook does not use

DocBook's "lang" attribute the way I expected. I was hoping, that if I had:

        <para lang="en_na">

                 Some English text.

        </para>

        <para lang="ja_ja">

                Japanese translation of the English text.

        </para>

then, I would be able to pass the desired langauge as a parameter to the 

a transform processor, and get only the <para/> elements with the 

matching lang attribute value.

The benefit of being able to do this, is that the consistency of the original

and the translations can be checked very easily. 

Is this line of thinking completely out of the area of discussions or development

in the DocBook world?

Would the correct approach be to concoct my own DocBook derived schema

with tags to manage translations, and then write my own XSL (or other) transforms

to produce a single langauge DocBook file?

Thank you.

Taro Ikai