Private Sub MDIForm_Load()
    Form1.Show
End Sub

Option Explicit
 
Private Declare Function SetWindowPos Lib "user32.dll" (ByVal hwnd As Long, _
  ByVal hWndInsertAfter As Long, ByVal x As Long, ByVal Y As Long, ByVal cx As _
  Long, ByVal cy As Long, ByVal wFlags As Long) As Long
 
Private Const SWP_NOMOVE = 2
Private Const SWP_NOSIZE = 1
Private Const HWND_FLAGS = SWP_NOMOVE Or SWP_NOSIZE
Private Const HWND_TOP = 0
Private Const HWND_TOPMOST = -1
Private Const HWND_NOTOPMOST = -2
 
Private Sub Command1_Click()
    Call SetWindowPos(Me.hwnd, HWND_TOPMOST, 0, 0, 0, 0, HWND_FLAGS)
End Sub
 
Private Sub Command2_Click()
    Call SetWindowPos(Me.hwnd, HWND_NOTOPMOST, 0, 0, 0, 0, HWND_FLAGS)
End Sub