[API problem] can I get magnification factor?

i want to get window magnifier's magnification factor,

launch the magnifier (window key, +,+) and run this code

i don't know at all how to get the factor

Public Declare Function MagInitialize Lib "magnification.dll" () As Boolean
Public Declare Function MagUninitialize Lib "magnification.dll" () As Boolean
Public Declare Function MagGetFullscreenTransform Lib "magnification.dll" _
(ByVal pMagLevel As Single, ByVal pxOffset As Integer, ByVal pyOffset As Integer) As Boolean '

Sub testf9024()
If (MagInitialize) Then
MsgBox hwnd <---magnification.factor
End If
End Sub