Werte zuweisen per Makro in xy Diagramm

Sub chartCreator()
Dim myDiagram As ChartObject
Dim myDataserie As Series
Dim strName As String
For y = 1 To 3 Step 1
ActiveWorkbook.Worksheets(7).Activate
strName = Worksheets(1).Range("A1")
Set myDiagram = ActiveSheet.ChartObjects.Add _
(Left:=0, Width:=720, Top:= _
Switch(y = 1, 0, y = 2, 408, y = 3, 816), Height:=396)
myDiagram.Chart.ChartType = xlXYScatterLines
'Es sollen 3 Reihen erstellt werden
For x = 1 To 3 Step 1
strName = Switch(x = 1, ActiveWorkbook.Worksheets(1).Range("A1"), _
x = 2, Worksheets(1).Range("J1"), _
x = 3, Worksheets(1).Range("S1"))
Set myDataserie = myDiagram.Chart.SeriesCollection.NewSeries
With myDataserie
.Name = strName
.XValues = "=Tabelle1!R5C2:R14C2"
.Values = "=Tabelle1!R5C7:R14C7"  'und bei dieser Zuweisung kommt Fehler
End With
Next
'nun kommen Beschriftung und Formatierung von Titel,X-Achse und Y_Achse
End Sub