Помню, что-то такое делал :)

Но помоему это через API

'SetWindowPos flags
Private Const SWP_NOSIZE = &H1
Private Const SWP_NOMOVE = &H2
Private Const SWP_NOZORDER = &H4
Private Const SWP_NOREDRAW = &H8
Private Const SWP_NOACTIVATE = &H10
Private Const SWP_FRAMECHANGED = &H20
Private Const SWP_SHOWWINDOW = &H40
Private Const SWP_HIDEWINDOW = &H80
Private Const SWP_NOCOPYBITS = &H100
Private Const SWP_NOOWNERZORDER = &H200
Private Const SWP_DRAWFRAME = SWP_FRAMECHANGED
Private Const SWP_NOREPOSITION = SWP_NOOWNERZORDER

'SetWindowPos hwndInsertAfter values
Private Const HWND_TOP = 0
Private Const HWND_BOTTOM = 1
Private Const HWND_TOPMOST = -1
Private Const HWND_NOTOPMOST = -2

Private Declare Function SetWindowPos _
Lib "user32" ( _
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


'~~~.OnTop
Public Function mdlWindowOnTop(frm As Object, Setting As Boolean) As Boolean
'Set form's OnTop property
'Private mbOnTop As Boolean

If Setting Then
'Make this form topmost
SetWindowPos frm.hwnd, HWND_TOPMOST, _
0, 0, 0, 0, SWP_NOMOVE Or SWP_NOSIZE
Else
'Make this form non-topmost
SetWindowPos frm.hwnd, HWND_NOTOPMOST, _
0, 0, 0, 0, SWP_NOMOVE Or SWP_NOSIZE
End If
mdlWindowOnTop = Setting
End Function

Зато мой вариант, вообще, поверх всех окон :)
Даже других приложений :)