There should be a way to keep two versions in one word document. The main
rule would be only use paragraphs pair wise. For every headline style a
pair, for all body text a pair. For the output language A you get a macro to
make language B as hidden text and for the other language the other way
around.

My question is, if there already is some kind of VBA application to handle
that kind of task?

Michael Müller