Private Sub Toolbar1_ButtonClick(ByVal Button As MSComctlLib.Button)

    Select Case Button.Key
        Case "Exit"
            Unload Me
            
        Case "Refresh"
            '...
     
    End Select
End Sub

Private Sub CommandButton1_Click()
  HandleButtonsClicks CommandButton1
End Sub

Private Sub CommandButton2_Click()
  HandleButtonsClicks CommandButton2
End Sub

Private Sub HandleButtonsClicks(ByVal Btn As Object) 'или ByRef, и Btn As MSForms.CommandButton, но так глючат свойства некоторые
  Select Case Btn.Caption 'или Btn.Name
 '...

 End Select
End Sub