Hi Bigguy55,
This is indeed possible with the Qu’s USB B interface. Any channel can be sourced from USB or a preamp, and this will correspond to the signal that comes into this channel. If the preamp is chosen, you would create a track in your DAW to capture the incoming signal from the channel. If USB is chosen, you would output your recorded track from the DAW to playback through the channel on the mixer.
I hope this makes sense, and please start a ticket at support allen-heath.com if you would like further assistance.
Thanks! Alex