Sheldon,

The best option is to create the commandbar on the fly, when the workbook is
opened, and delete the commandbar when the workbook is closed. Follow these
instructions and example code.

In the workbook's Thisworkbook object code module, place the following code:

Private Sub Workbook_BeforeClose(Cancel As Boolean)
DeleteCommandbar
End Sub

Private Sub Workbook_Open()
CreateCommandbar
End Sub

Private Sub Workbook_WindowActivate(ByVal Wn As Window)
  On Error GoTo NotThere
  Application.CommandBars("My Bar").Visible = True
  Exit Sub
NotThere:
  CreateCommandbar
End Sub

Private Sub Workbook_WindowDeactivate(ByVal Wn As Window)
  On Error Resume Next
  Application.CommandBars("My Bar").Visible = False
End Sub

In a regular code module, place the following:

Dim myBar As CommandBar
Dim myButton As CommandBarButton

Sub CreateCommandbar()

On Error Resume Next
DeleteCommandBar

Set myBar = Application.CommandBars.Add("My Bar")
With myBar
  .Position = msoBarTop
  .Visible = True
  .Enabled = True
  Set myButton = .Controls.Add(Type:=msoControlButton, ID:=23)
  With myButton
      .Caption = "Hello"
      .Style = msoButtonIcon
      .FaceId = 137
      .Enabled = True
      .OnAction = "SayHello"
  End With
End With

End Sub

Sub DeleteCommandBar()
'Delete the commandbar if it already exists
  On Error Resume Next
  Application.CommandBars("My Bar").Delete
End Sub

Sub SayHello()
MsgBox "Hello there"
End Sub

You can add as many buttons or other menu items as you like.

HTH,
Bernie
MS Excel MVP