=SI(ESTERR(INDEX(A2:D88;EQUIV(G2;DECALER(A2:A88;0;SOMMEPROD((A2:D88=G2)*COLONNE(A2:D88))/NB.SI(A2:D88;G2)-1);0);EQUIV(G3;A1:D1;0)));G2;INDEX(A2:D88;EQUIV(G2;DECALER(A2:A88;0;SOMMEPROD((A2:D88=G2)*COLONNE(A2:D88))/NB.SI(A2:D88;G2)-1);0);EQUIV(G3;A1:D1;0)))