c++ – Wasapi : how to create a router mixer

I’m trying to create a mixing table with Wasapi.
I create and retrieve samples from Input Card then send it to Output Speaker.

But how to create matrix with subvoice that will not being playing through Speaker ?
I can’t found any documentation on MSDN.

Maybe :
IAudioClient always depend on a IMMDevice, but is it possible to create an IAudioClient with both IAudioRenderClient and IAudioCaptureClient, this way i can send sample to the IAudioRenderClient and then retrieve sample from the IAudioCaptureClient to send it anew to another IAudioRenderClient this time linked to a device or to a file by example ?