Silly Excel thingy

Public DataLen As String 'number of rows in the dataset including the headers, gets autoset in the resetbuttons sub
Public Const DataSheet As String = "Data"
Public Const ChartSheet As String = "Crunch"
Public Const TableName As String = "Table_DB2_DB2_VMI_PerformanceCounter_TraceView_DB2" 'Table name in the datasheet

Public Sub ResetButtons()
On Error GoTo Error_Handler
Dim t As ListObject
Dim i As Long
Dim b As Button
Set t = Sheets(DataSheet).ListObjects.Item(TableName)
DataLen = t.DataBodyRange.Rows.Count + 1
Debug.Print DataLen
    For Each b In Sheets(ChartSheet).Buttons
        If b.TopLeftCell.Cells.Row = 1 And b.TopLeftCell.Cells.Column = 18 Then
        'b.Name = "btnReset"
        b.Caption = "Reset Buttons to Data Columns"
        b.OnAction = "ResetButtons"
        'Debug.Print b.Name
        Else

        b.Caption = "" 't.ListColumns.Item(i).Name
        b.OnAction = "" '"Sheet1.s" & Format(i, "00") & "_Click"
        End If
    Next b
For i = 2 To t.ListColumns.Count
'Debug.Print t.ListColumns.Item(i).Name
    For Each b In Sheets(ChartSheet).Buttons
        If b.TopLeftCell.Cells.Row = i Then
        'Debug.Print b.Name
        b.Caption = t.ListColumns.Item(i).Name
        b.OnAction = "s" & Format(i, "00") & "_Click"
        End If
    Next b
Next i
Error_Exit:
Exit Sub
Error_Handler:
    MsgBox "The following error has occured" & vbCrLf & vbCrLf & _
           "Error Number: " & Err.Number & vbCrLf & _
           "Error Source: ResetButtons" & vbCrLf & _
           "Error Description: " & Err.Description _
           , vbOKOnly + vbCritical, "An Error has Occured!"
Resume Error_Exit
End Sub

Public Function ChangeChart(argCol As Long)
Dim chart As ChartObject
For Each chart In Sheets(ChartSheet).ChartObjects

    Dim ser As Series
    chart.chart.ChartTitle.Text = Sheets(DataSheet).Cells(1, argCol).Value
    For Each ser In chart.chart.SeriesCollection
        'Debug.Print ser.Formula
        ser.Formula = "=SERIES(," & DataSheet & "!$A$2:$A$" & DataLen & "," & DataSheet & "!$" & ColLtr(argCol) & "$2:$" & ColLtr(argCol) & "$" & DataLen & ",1)"
    Next ser

Next chart
End Function

Public Function ColLtr(ByVal iCol As Long) As String
    ' shg 2012
    If iCol Then ColLtr = ColLtr((iCol - 1) \ 26) & Chr(65 + (iCol - 1) Mod 26)
End Function

Public Sub s02_click()
ChangeChart 2
End Sub
Public Sub s03_click()
ChangeChart 3
End Sub
'This goes on for about 99 buttons.