[FFmpeg-user] How can I replace numbered sound tracks in my AVI ?

[Olivier Soleil]

Hello everyone, this is my first post here, hope it's gonna be interesting and fruitful.
Let's say that I have to produce CGI movies for a game, and voiced tracks (ENG, FRA, ...) are located above stream 100.
So, I have a video track on the 0 stream, surround ambient sounds located between 1-5 streams, and voiced tracks above 100th stream.

Well, it may look crazy, but why not ?
Every time the soundmix for a language is updated, I would like to replace the old one with the new one, without changing the rest of the data in the AVI. Working this way is very easy with Bink, but I don't see how the available options of FFMPEG would allow this kind of manipulations.
I still hope someone here can answer me. Please ?

Thank you for your attention.