re,
à tester,
Sub test()
Dim r1 As String, r2 As String, i As Integer, t As String
r1 = Range(Cells(1, 1), Cells(10, 1)).Address(0, 0)
r2 = Range(Cells(1, 2), Cells(10, 2)).Address(0, 0)
For i = 1 To 10
t = "INDEX(" & r2 & ",SMALL(IF((" & r1 & "=A" & i & "),ROW(" & r1 & "),""""),COUNTIF($A$1:A" & i & ",A" & i & ")))"
Cells(i, "H") = Evaluate(t)
Next i
End Sub