@capink Thanks. I managed to figure out some stuff while waiting for the post to be approved and i was able to achieve what i needed. I made a custom column that associates French or English depending on language retried when i retrieve the metadata.
Custom Column >
Code:
Column type: Column built from other columns
Template: program: if field('languages') == 'fra' then 'french' else 'english' fi
Sort/search column by: text
and set save to disk path to
Code:
{#language}/{author}/{series:||/}{series_index:0>2s| | - }{title}/{title} - {author}