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
Private Const SWP_NOMOVE = &H2
Private Const SWP_NOSIZE = &H1
Private Const HWND_TOPMOST = - 1 
Private Const HWND_NOTOPMOST = - 2 

Call SetWindowPos(frmMain.hwnd, HWND_TOPMOST,  0 ,  0 ,  0 ,  0 , SWP_NOMOVE Or SWP_NOSIZE) 'форма поверх всех