plugin - SATB file -> export specific part + piano as .mscz

Hello,

I am singing in a choir.
I already have the complete scores as .mscz (SATB + piano) for all the works we'll sing this year.
I would like to provide my colleagues with a set of Musescore files :

1. one S/A/T/B voice alone (music + lyrics) -> thus 4 .mscz files

2. one S/A/T/B voice + piano (volume 100% / 30%) -> thus 4 .mscz files

3. one S/A/T/B voice + 3 others + piano (volume 100% / 30% / 30%) -> thus 4 .mscz files

I would like to automate this process via a plugin,.
I am OK coding it, but I didn't find in the docs anything that allows me to do this.

Any clue ?

Many thanks
Eric