Imports Extensibility
Imports System.Runtime.InteropServices
Imports Microsoft.Office.Core
Imports Microsoft.Office.Core.MsoAlertButtonType

Implements Extensibility.IDTExtensibility2
Dim WithEvents MyButton As CommandBarButton
Private applicationObject As Object 
Private addInInstance As Object

Public Sub OnStartupComplete(ByRef custom As System.Array) Implements Extensibility.IDTExtensibility2.OnStartupComplete
      Dim oCommandBars As CommandBars
        Dim oStandardBar As CommandBar
        Dim oBarPopup As CommandBarPopup
        On Error Resume Next
        oCommandBars = applicationObject.CommandBars
        oStandardBar = oCommandBars.Item("Standard")
        oBarPopup = oStandardBar.Controls.Add(Type:=msoControlPopup, Temporary:=True)
        oBarPopup.Caption = "COMAddIn"
        MyButton = oBarPopup.Controls.Add(Type:=msoControlButton)
        With MyButton
            .Caption = "Hide and unhide worksheets"
            .Style = MsoButtonStyle.msoButtonCaption
            .Tag = "My Custom Button"
            .OnAction = "!<MyCOMAddin.Connect>"
            .Visible = True
        End With
        oStandardBar = Nothing
        oCommandBars = Nothing
    End Sub