permuter la fonction somme

=DECALER(A3;;COLONNE($A:A)-1)+DECALER(A3;;COLONNE($A:A))

=DECALER(A3;;COLONNE($A:A)-1)+DECALER(A3;;COLONNE($A:A)+1)

Option Explicit

Function SommeC2#(R As Range, n&)
    Dim c1 As Range, c2 As Range, c&, o%
    If (R.Columns.Count > 1 And R.Rows.Count > 1) Or R.Count = 1 Then
        SommeC2 = CVErr(xlErrRef)
        Exit Function
    End If
    If n < 1 Or n > WorksheetFunction.Combin(R.Count, 2) Then Exit Function
     If R.Columns.Count > 1 Then o = 1
     For Each c1 In R
        For Each c2 In R
            If Not (c1.Row = c2.Row And c1.Column = c2.Column) Then
                Select Case o
                    Case 1
                        If c2.Column > c1.Column Then
                            SommeC2 = c1 + c2
                            c = c + 1
                            If c = n Then Exit Function
                        End If
                    Case 0
                        If c2.Row > c1.Row Then
                            SommeC2 = c1 + c2
                            c = c + 1
                            If c = n Then Exit Function
                        End If
                End Select
            End If
        Next c2
    Next c1
End Function