Open QMainWindow to use xterm window as parent

I use this "terminator" xterm app from ubuntu that allows you to split multiple xterms into one window. Now I wan to open in one of them emacs and in the other my Qt application (from than on behaving as if it is the xterm window child (resizing etc respected).

Again, the parent will be a foreign, X11 or something window, not Qt window.

Thanks in advance !