哪位大神能帮我解释一下这个宏命令，感谢！

excel初级菜鸟

Private Sub Workbook_BeforeClose(Cancel As Boolean)
    删除自定义菜单 Application.CommandBars("Worksheet Menu Bar"), "输出凭证"
End Sub

Private Sub Workbook_Open()
    Dim mainmenu As Variant
    Set mainmenu = Application.CommandBars("Worksheet Menu Bar")
    删除自定义菜单 mainmenu, "输出凭证"
    Set cwbutton = mainmenu.Controls.Add(Type:=msoControlButton)
        With cwbutton
            .BeginGroup = True
            .Style = msoButtonIconAndCaption
            .FaceId = 271  '238
            .Caption = "输出凭证"
            .OnAction = "凭证接口.输出凭证TXT"
            .TooltipText = "单击此输出凭证接口文件"
    End With
    ActiveWorkbook.Saved = True
End Sub

Sub 删除自定义菜单(barname As Variant, CdName As String)
   For Each Btn In barname.Controls
       If Btn.Caption = CdName Then Btn.Delete
   Next Btn
End Sub