In Mode 2 U2 the BCR has two independent Midi interfaces to the PC via USB.
BCR 1 In and Out is the BC itself and BCR 2 In and Out are just the Midi ports (In Port & Out Port A) on the back of the unit.
Connect the synth to the BCR Midi Ports.
Connect BC Manager to BCR 1 In and Out.
As the Behringer Midi driver is multi client, you can run more than one program connected to the same midi ports at the same time.
Start Midi Ox and connect BCR1 In to BCR2 Out and now movement on the BCR will send Midi to the synth. Connecting BCR2 In to BCR1 Out will provide feedback to the BC controls from the synth (if it is capable of that and has been set up to do that).
Although the BC will send sysex back to BC Manager and this will be also sent to the synth, the synth will ignore it.
All the best
Royce