addChild my window to other application's window

I ne开发者_开发知识库ed to add my NSWindow as a child to window of other application.

I want to use - (void)addChildWindow:(NSWindow *)childWindow ordered:(NSWindowOrderingMode)orderingMode

But I know the ID of that window. How I can get windowRef of that window?

Those windows don't belong to you so you're not going to get the window reference you need to use this method. Your best bet is to use the Accessibility API to watch the desired window and move your own window to the desired position when the target window is moved or resized.