how to set up auxillary channel

A bit baffled on this, I just procured a space echo and would like to use it as an effects send, not an insert.
I have plenty of ins and outs but cant seem to get it to work, problem is, what is the best way to get the mono signal out of cubase I can use a cue send and it works fine but i am sure there must be a better way.
the return is straight forward as i can just use 2 audio tracks with the monitors left active.
any help appreciated.

win 7 64bit yamaha 01v96i interface

Why not add it as an external effect?