Si lo que quieres es que tu aplicación se encuentre al frente de todas las ventanas en Windows (que redundante):
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
Const HWND_NOTOPMOST = -2
Const HWND_TOPMOST = -1
Const HWND_BOTTOM = 1
Const SWP_NOSIZE = &H1
Const SWP_NOMOVE = &H2
Private Sub Command1_Click()
'Trae al frente de todas las ventanas al form1 aunque cambies de ventana (StayOnTop)
Dim flags As Long
Dim retval As Long
flags = SWP_NOSIZE Or SWP_NOMOVE
retval = SetWindowPos(Form1.hwnd, HWND_TOPMOST, 0, 0, 1, 1, flags)
End Sub
Private Sub Command2_Click()
'Si cambias de ventana ya no estará al frente el form1
Dim flags As Long
Dim retval As Long
flags = SWP_NOSIZE Or SWP_NOMOVE
retval = SetWindowPos(Form1.hwnd, HWND_NOTOPMOST, 0, 0, 1, 1, flags)
End Sub
Private Sub Command3_Click()
'Manda al fondo tu ventana (form1) y se pierde el 'StayOnTop'
Dim flags As Long
Dim retval As Long
flags = SWP_NOSIZE Or SWP_NOMOVE
retval = SetWindowPos(Form1.hwnd, HWND_BOTTOM, 0, 0, 1, 1, flags)
End Sub