Sub Test_D()
Dim Ligne&, Rng As Range, col_MaX$, col_MiN$
Dim f As Worksheet: Set f = Sheets("RECAP")
With Application
Ligne = .Match(Sheets("GRAPH").[B1], f.[A:A], 0)
Set Rng = Sheets("RECAP").Rows(Ligne)
col_MaX = f.Cells(1, .Match(.Max(Rng), Rng, 0) + 2)
col_MiN = f.Cells(1, .Match(.Min(Rng), Rng, 0) + 2)
End With
MsgBox "Max: " & col_MaX & Chr(13) & "Min: " & col_MiN, vbInformation, "Résultats"
End Sub