HWND on Win32 API to Qt widget

[delio]

I've write win32 API program but GUI creating is too hard and ugly for me.
So I want Qt GUI but I have to use Win32 command.

How to convert HWND on Win32 API to Qt widget?
I know that I have to use QWidget::winId().
but I don’t know how to write it
Please give me an example.

Thanks