Finding/Changing Range from existing Excel Chart

[campster]

Here's the solution that I came up with. Is there a better way?

Public Sub setSeriesLength()
 
        Dim oShtData As Excel.Worksheet
        Dim oSeries As Excel.Series
        Dim rng As String
        Dim tRng As String
        Dim tempRng As String
        Dim strAlpha() As String
 
        oShtData = CType(oExcel.Workbooks(1).Worksheets("data"), Excel.Worksheet)
        Dim rows As Integer = oShtData.UsedRange.Rows.Count
        tRng = "A2:A" & rows
        rng = ""
 
        For Each oCht As Excel.Chart In oExcel.Workbooks(1).Charts
            Dim cnt As Integer = CType(oCht.SeriesCollection, Excel.SeriesCollection).Count
            rng = ""
            For i As Integer = 1 To cnt
                oSeries = oCht.SeriesCollection(i)
                tempRng = CType(oCht.SeriesCollection, Excel.SeriesCollection).Item(i).Formula
                strAlpha = tempRng.Trim.Split("$"c)
                If strAlpha(0).ToLower.Contains("data") Then
                    tempRng = strAlpha(UBound(strAlpha) - 1) & "2:" & strAlpha(UBound(strAlpha) - 1) & rows
                    If (Len(rng) > 0) Then
                        rng = rng & "," & tempRng
                    Else
                        rng = tempRng
                    End If
 
                    oSeries.Values = oShtData.Range(rng)
                    oSeries.XValues = oShtData.Range(tRng)
                End If
                
            Next
            oCht.SetSourceData(oShtData.Range(tRng & "," & rng), Excel.XlRowCol.xlColumns)
 
        Next
    End Sub