The WindowFromAccessibleObject function retrieves the window handle that corresponds to a given instance of an IAccessible interface.

public static extern uint WindowFromAccessibleObject(IAccessible pacc, ref IntPtr phwnd );

Declare Function WindowFromAccessibleObject Lib "oleacc.dll" (ByVal pacc as IAccessible, ByRef phwnd as IntPtr) As Integer

        WindowFromAccessibleObject(iAccessible, ref handler);

    public static extern uint WindowFromAccessibleObject(IAccessible pacc, ref IntPtr phwnd);