how to use cvGetWindowName from QWidget?

Hi,
I have this problem, I have application in Qt and I have plug-in in only OpenCv.
I need to use function cvGetWindowName in my application to get window name
for plug-in. In plug-in image shows. I do not need to show new window, but to show in my application window.

For example:
...
Gui window;
const char *cvWindow = cvGetWindowName(window.uiGui->qwidget);
cvShowImage(cvWindow, img);
window.show();
...

Have a look at QWidget::windowTitle ().