4CM:
Guitar -> 11R input
11R FX Send-> Fender HRD input
Fender HRD Send -> 11R FX Return
11R Amp2 Output -> Fender HRD Return

Just place the fx loop in the 11R rigs depending of what you need the 11R to do:
You can use the 11R as a pedalboard to your Fender HRD
You can use the Fender HRD as a poweramp/cab for your 11R