Ho risolto, :mavieni: , penso che può essere utile a molti;
la procedura è:

"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" e con la Sub:
"Private Sub AlwaysOnTop(Frm As Form, OnTop As Boolean)"

Un saluto, by-by