OK after studying and experimenting a few pioneering hours (since I could not comprehend the documentation well nor the web info on this)
1) Using the OC control panel, set up to multiple monitors.
2) Connected Adams monitors to OC Output Jacks 3-4 (Instead of 1-2 (Mains))
3) Plugged the headphones to the OC front headphone jack (which the device recognized) ...
4) and
-- adjusted the Wave-Out 1-2 on Direct Mixer A for the headphones
-- adjusted the Wave-Out 1-2 on Direct Mixer B for the Adams (active) Monitors
(So there it is! I hope this helps any of you other OC noobs who monitor independently with headphones and active monitors)