Logic Pro 9 Controlling Reason faders via midi in Logic

Hey guys,

So I'm fairly new to Logic, and a long-time Reason/Protools user. I have figured out how to rewire the audio from Reason to Logic, but have yet to figure out how to use Logic to control the faders and knobs of Reason devices. Volume of each reason device is my primary concern here.

Let's say I record a keyboard part in Logic, and it's too loud in the mix. Sure, I can flip over to reason and turn it down, but I'd rather have a dedicated fader in Logic too. That way I can see all the automation and faders in one place. How do I send that midi signal?