I want to create a chart with 1 serie which has data from 4 discontiguous
cells.
I defined 'b=6' but in practice it has a variable value, also counter has
variable values.
I tried two methods:
1/ with the union method to make a multirange selection
2/ by combining the cell addresses to a string.
None of these works. How do I solve this?

thanx in advance

Sub Macro1()
 Charts.Add
 With ActiveChart
   .ChartType = xlColumnClustered
   .SetSourceData Source:=Sheets("Summery").Range("A21:I40"), PlotBy:=xlRows
   .SeriesCollection.NewSeries
   .SeriesCollection(1).XValues = "={""x1"",""x2"",""x3"",""x4""}"
   
   Set temprange = Range(Cells(2, b))
   For counter = 4 To 8 Step 2
     Set temprange = Union(temprange, Range(Cells(counter, b)))
   Next
    .SeriesCollection(1).Values = temprange

   'tempstring = Cells(2, b).Address
   'For counter = 4 To 8 Step 2
   '  tempstring = tempstring & "," & Cells(counter, b).Address
   'Next
   '.SeriesCollection(1).Values = range(tempstring)
   
   .SeriesCollection(1).Name = "=""test"""
   .Location Where:=xlLocationAsObject, Name:="Summery"
 End With
End Sub