Redirect Audio Output to Audio Input

Hello everybody. I have the task to redirect Audio Output Signal from USB Audio Interface to Input Audio Signal which i’ll be recording and playing with Qt MultiTrack Application. For more information about the my vision of this task see the scheme below. Are there the Qt сlasses which can help me? I tried to use the QAudioRecorder, but it class uses as input device only real input device like Realtek HD Audio Input for example.