Using
a Multiple Document Interface
Applications
that use a multiple document interface (MDI) might need to specify window
styles that are not available through the MCIWndCreate function. For these
applications, you can register and create an MCIWnd window by using the MCIWndRegisterClass function with the CreateWindowEx function. The MCIWndRegisterClass
function registers the MCIWND_WINDOW_CLASS window class and then CreateWindowEx
creates an instance of an MCIWnd window.