Selecting prefered language in console like for sub

Hi all,
I'm currently looking how to force Serviio to transcode a specific audio track instead of the first one.
I understand we can create a specific transcoding profile for audio type like DTC or AC3.
But in my case I want to use only French audio track.
Mkv used for source files and tag are specified so in the mkv header we know language of each tracks.
It's already working fine with subtitle, I want just to do the same for audio.
I know I can remux files with mkvmerge but I have a lot of files not really quick to do.
Any idea?
Help will be appreciated.
Cheers.
I'm currently looking how to force Serviio to transcode a specific audio track instead of the first one.
I understand we can create a specific transcoding profile for audio type like DTC or AC3.
But in my case I want to use only French audio track.
Mkv used for source files and tag are specified so in the mkv header we know language of each tracks.
It's already working fine with subtitle, I want just to do the same for audio.
I know I can remux files with mkvmerge but I have a lot of files not really quick to do.
Any idea?
Help will be appreciated.
Cheers.