How to configure dual PC streaming setup with capture card?

[techoverclock0]

Hello,
I am planning to build a streaming setup. I have my laptop ASUS ROG with GTX1050 GPU and Intel® Core™ i7 7700HQ Processor. I play games on this laptop with a gaming keyboard, mouse, headset and external monitor attached to laptop. Together with that I have an old PC sitting doing nothing having AMD A8 6600k APU, I was thinking of using that old PC as streaming PC by equipping it with a capture card.
I have nothing connected to PCIe lanes so all lanes are free for capture card.
Now my question is:
Since I am using headset for my primary audio audio output as well as input, means the audio is not sent over the HDMI which goes to the monitor, now I want that audio to broadcast also along-with sending it to my headset. I can select only 1 primary audio output in Windows, how can I configure it so that it will send all the audio to HDMI also?

Any help is really appreciated
Thank you
Regards

 

[americanaudiophile]

One of these might help
https/github.com/audiorouterdev/audio-router
https/www.vb-audio.com/Cable/index.htm
http/www.chevolume.com/