translation management

Hello,

Assuming that I have a DocBook document in a source and a target language
and  the source language is changing .

Step 1: When I check out the  book for translation how can I identify the
parts the author has changed (I assume that the author markes the revision
with the revisiontag=changed) and give a extract to the translator with
only these changed parts. Does that work with profiling and how do I
profile only the changed content?
Step 2: After the translation I want to integrate the translated version of
this extract into the target language file so that source and target
language have the same revision status.

Is there a tool or easy way to handle that? The translators are using
Translation Memory Technology so if I would give the result of step1 to
them they might integrate the translated segments with their translation
memory and step 2 would be not necessary

regards

René Feuchtinger