Hello -- I have both Adobe Audition CS6 and Creative Cloud.
It used to be, on my Windows computer, I could simultaneously record from a line-out or headphones out on a camera, or audio-recorder, into the line-in on a laptop straight into Adobe Audition (then called "Final Edit") in real-time.
You don't say anything about the sound card in your MacBook Pro, so I would assume that they use an onboard card, but there should be some sort of control panel for levels going in to and out of the card.
A microphone input is typically a very low level signal, and is mono. A line in will be expecting a much higher input level, and will usually be stereo.
The sound card should have an additional pre-amp stage for the mic to bring it up to line levels. Here's a rundown on the internal card (probably Intel):