Simultaneous Host microphone input to Host audio output

How do I get the hosts microphone input to also go out the hosts computers audio output at the same time.  I realize normally this would not be something a host would want.  However we have a need to stream the hosts computers video input and microphone input to an in house CCTV system.  The host computer is connected to a QAM modulator through the HDMI output of the computer.  So now only video and audio of the participants is being streamed to our CCTV system.  Only the hosts video is streamed and their microphone input is not.