Yes, I think I found the COPA office at the west end of the second level. However, all the lights were off and the whole area was deserted. I asked at an information booth where I could find a COPA employee, and they tried to point me inside the international departures area. It appeared that I would need a valid ticket to get inside there, though. Definitely wouldn't have minded getting an IDB rate, if that level of discount is normal! I paid the rack rate at the Holiday Inn, but after about 45 hours of travel, I decided I would pay anything halfway reasonable to get a comfortable bed ASAP.

I think the lesson here is that there wasn't any rush to find LAN and make sure my ticket for the next morning was straightened out, since their operations never shut down. I should have stopped at the door of the aircraft and asked where to go for COPA assistance.

As an aside, my bag arrived 3 days later up in La Serena. It's a good thing I'm here on a fairly long visit, or else it would have arrived after I left to go home.