Sub Test_VAL_Index()
Dim n%, t
n = Val(InputBox("Nombre de cellules à valider sur G3:WQP3 :", 16000, "Test validation"))
If n < 1 Then Exit Sub
t = Timer
[G3].Resize(, n) = "=INDEX($B3:$C8002,1+INT((COLUMNS($G3:G3)-1)/2),1+MOD(COLUMNS($G3:G3)-1,2))"
Debug.Print "Durée validation => " & Format(Timer - t, "0.00 \s"), , "Test validation"
End Sub