Private Sub Form1_Load(sender As Object, e As EventArgs) Handles Me.Load
    Me.ButtonChildTitle.Visible = False 'но handle уже существует, т.к. в конструкторе .Visible = True
  End Sub

  Private Sub Form1_Load(sender As Object, e As EventArgs) Handles Me.Load
    'секретная кнопка(невидимая, нулевых размеров и без TabStop) -по ее тексту проверяем окно
    CreateTheButton(Me.Handle, 0, 0, 0, 0, _
     WS_CHILD Or BS_DEFPUSHBUTTON, "blabla-bla qwertyuio")
  End Sub

'====
  'Window Styles
  Public Const WS_CHILD = &H40000000
  Public Const WS_VISIBLE = &H10000000

  'Button Styles
  Public Const BS_DEFPUSHBUTTON = &H1&

  <StructLayout(LayoutKind.Sequential)>
  Public Structure RECT
    Dim Left As Integer
    Dim Top As Integer
    Dim Right As Integer
    Dim Bottom As Integer
  End Structure

  Public Declare Function GetClientRect Lib "user32" _
   (ByVal hwnd As IntPtr, ByRef lpRect As RECT) As Boolean
  Public Declare Unicode Function CreateWindowEx Lib "user32" Alias "CreateWindowExW" _
   (ByVal dwExStyle As Integer, ByVal lpClassName As String, ByVal lpWindowName As String, _
   ByVal dwStyle As Integer, ByVal x As Integer, ByVal y As Integer, ByVal nWidth As Integer, _
   ByVal nHeight As Integer, ByVal hwndParent As IntPtr, ByVal hMenu As IntPtr, _
   ByVal hInstance As IntPtr, ByRef lpParam As Object) As IntPtr

  Public Function CreateTheButton(ByVal hWndParent As IntPtr, ByVal Left As Integer, _
   ByVal Top As Integer, ByVal Width As Integer, ByVal Height As Integer, _
   ByVal ButtonStyle As Integer, Optional ByVal ButtonText As String = vbNullString) As Long

    Dim rcClient As RECT
    GetClientRect(hWndParent, rcClient)

    CreateTheButton = CreateWindowEx(0, _
     "BUTTON", _
     ButtonText, _
     ButtonStyle, _
     rcClient.Left + Left, _
     rcClient.Top + Top, _
     Width, _
     Height, _
     hWndParent, _
     IntPtr.Zero, _
     System.Runtime.InteropServices.Marshal.GetHINSTANCE _
      (System.Reflection.Assembly.GetExecutingAssembly.GetModules()(0)).ToInt32(), _
     Nothing)
  End Function