Encontré ésto en la web (http://www.elguille.info/vb/VB_API01.HTM#api006)
6.- Dejar una ventana siempre visible
De nuevo usaremos el API de Windows: SetWindowPos
'Declaración para usar ventanas siempre visibles
'Versión para 16 bits
Declare Function SetWindowPos Lib "User" (ByVal hWnd As Integer, ByVal hWndInsertAfter As Integer, ByVal X As Integer, ByVal Y As Integer, ByVal cx As Integer, ByVal cy As Integer, ByVal wFlags As Integer) As Integer
'Versión para 32 bits
Declare Function SetWindowPos Lib "User32" Alias "SetWindowPos" (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
' SetWindowPos Flags
Const SWP_NOSIZE = &H1
Const SWP_NOMOVE = &H2
'Const SWP_NOZORDER = &H4
'Const SWP_NOREDRAW = &H8
Const SWP_NOACTIVATE = &H10
'Const SWP_DRAWFRAME = &H20
Const SWP_SHOWWINDOW = &H40
'Const SWP_HIDEWINDOW = &H80
'Const SWP_NOCOPYBITS = &H100
'Const SWP_NOREPOSITION = &H200
Const SWP_FLAGS = SWP_NOMOVE Or SWP_NOSIZE Or SWP_SHOWWINDOW Or SWP_NOACTIVATE
'Código para poner en Form_Load
'De esta forma no es necesario usar una variable para asignar el valor devuelto:
If SetWindowPos(hWnd, -1, 0, 0, 0, 0, SWP_FLAGS) Then
End if
Espero te sirva
