VB使用mschart控件怎么标注下标你？？？困扰我好久，请高手指点

代码如下：
Private Sub Command1_Click()
Dim y
  MSChart1.chartType = VtChChartType2dBar
  
  MSChart1.RowCount = 1
  MSChart1.ColumnCount = 50
  For y = 1 To 50
   MSChart1.Column = y
   MSChart1.ColumnLabel = y
    If y Mod 2 = 0 Then
     MSChart1.Plot.SeriesCollection(y).DataPoints(-1).Brush.FillColor.Set 0, 0, 255
    Else
      MSChart1.Plot.SeriesCollection(y).DataPoints(-1).Brush.FillColor.Set 255, 0, 0
    End If
 Next

    With MSChart1.Legend
                  .Location.Visible = True
                  .Location.LocationType = VtChLocationTypeBottom
                  '设置图例属性。
                  .TextLayout.HorzAlignment = VtHorizontalAlignmentLeft
                  '使用黄色文本。
                  .VtFont.VtColor.Set 0, 0, 0
                  .Backdrop.Fill.Style = VtFillStyleBrush
                  .Backdrop.Fill.Brush.Style = VtBrushStyleSolid
                  .Backdrop.Fill.Brush.FillColor.Set 255, 255, 255
    End With

  MSChart1.TitleText = "调频点"
End Sub

如下图所示：