how to get aphex exciter enhancer working in logic pro x?!

so I've just gone ahead and bought an aphex exciter.. not any plug ins but the real thing. I'm quite an amateur at recording, so I've never been great using logic.

so I have connected the aphex going from the outputs on my focusrite saffire pro interface, then back into the saffire from the outputs on the aphex. on the saffire mix control I have the settings so analog 3 and 4 (I am using input 3 and 4 on interface for the exciter) are set to come out of the monitor output 1 and 2. so I can play music via the exciter which sounds amazing so far! much fuller and fatter sound!

so I'm really wanting to use it on my recordings that i create in Logic.. The question is how?! I've heard of using a bus, but I've never really understood how that works or how to do it. I have gone to the mixer in logic and on my output tried to see if it had an option, but then I've got the sound already coming straight from the aphex, so do I need to rewire my interface or saffire mix control settings to do this? and how would I go about getting the correct settings?

any help would be very much appreciated!