VBA Faire somme en horizontal et vertical

Private Sub Worksheet_Change(ByVal Target As Range)
Dim pl As Range, i As Range, r As Range, Dli As Long, Li As Long, Col As Byte, Col1 As Byte
Dim a&
Application.ScreenUpdating = False

If Not Intersect(Target, Range("H5:M20")) Is Nothing Then
a = Target.Row
    'Somme en N des lignes H5 à M20
    Range("N" & a) = Application.WorksheetFunction.Sum(Range("H" & a & ":M" & a))
    Range("O" & a) = Range("N" & a) * Range("D" & a)
    'Somme des colonnes N et O
    Range("N21") = Application.WorksheetFunction.Sum(Range("N" & a))
    Range("O21") = Application.WorksheetFunction.Sum(Range("O" & a))
End If

If Target.Count > 1 Then Exit Sub
  
  Application.EnableEvents = False
  
  If Not Intersect(Target, Range("A5:A20")) Is Nothing Then
    If Target.Value <> "" Then
        Target.Offset(0, 6).Value = Target.Value
        Target.Offset(20, 6).Value = Target.Value
        Target.Offset(39, 6).Value = Target.Value
        Target.Offset(58, 6).Value = Target.Value
    
        ElseIf Target.Value = "" Then
        Target.Offset(0, 1).Value = ""
        Target.Offset(0, 2).Value = ""
        Target.Offset(0, 3).Value = ""
        Target.Offset(0, 4).Value = ""
        Target.Offset(0, 6).Value = ""
        Target.Offset(20, 6).Value = ""
        Target.Offset(39, 6).Value = ""
        Target.Offset(58, 6).Value = ""
        
    End If
End If
Application.EnableEvents = True
Application.ScreenUpdating = True
End Sub