Where can I find out what a Level 4 French exam entails?
DGAC website?
But seriously, why? There are very few french only airfields, and plenty where either there is a controller, so you can do it in english, or radio not compulsory and according to my local DGAC office this means if it doesn't say french only you can do it in english. It might not do a lot for flight safety, but it is apparently legal.