Applescript to change a quicktime file audio from "4 mono" to "4 discrete" chanels

I have a bunch of Quicktime video files. Audio contained is "4 mono" chanels.

I'm looking for a way to change these chanels into "4 discrete" chanels.

This can be done manually in QT7 > windows > sequence properties. But I really have a bunch of files (daily) and I can't do that for each chanel of each file.

Would anyone know a way to make this automatically ?

Any help appreciated. Thanks in advance