You will want to take the trs output from the studio channel and connect it to the tr input (center of the multi-jack) on the front of the audiobox.
I would use a unbalanced tr->tr cable to make the connection. Keep the cable short if possible.
The problem is the audiobox inputs are not meant to utilize a line level signal coming from the studio channel, so you will need to be careful not to overload the instrument input of the audiobox.
There will be a large impedance mismatch between the two units, but it should be usable if you're careful with your gain staging.