There is an EXP desk in Ohare by ticketing.

I was bringing an elderly grandmother to her flight to FLL and needed a gate pass, she was was in first class, and all the first gate agents were busy so they sent me to the EXP agent (located right on the left of 1st class in ORD).

She warned me about the weather tomorrow, then we began talking about all my MR's, telling me how amazing of an idea this is and she can't believe I'm doing it. I told her to check out FT, and that from what I know there are 108 (107 on the list at beginning of this thread as of yesterday + me) of us doing it, she was floored!

After giving me a gate pass and switching my flights to the 24th, she welcomed me to AA and told me how she's looking forward to dealing with me as an EXP very soon.

Definitely a pleasant pre-welcome to AA EXP!!