=CHOISIR(ALEA.ENTRE.BORNES(1;3);
GAUCHE(B2;TROUVE(",";B2)-1);
STXT(B2;TROUVE(",";B2)+1;TROUVE(",";B2;TROUVE(",";B2)+1)-TROUVE(",";B2)-1);
STXT(B2;TROUVE(",";B2;TROUVE(",";B2)+1)+1;TROUVE(",";B2;TROUVE(",";B2;TROUVE(",";B2)+1)+1)-TROUVE(",";B2;TROUVE(",";B2)+1)-1))