There are two possibilities for a code that I can think of:
1) in the close-in parking there are bars that lay flat on the ground, kind of on a hinge; the car drives over it into the parking spot and the bar (at some point in time) can be raised to keep the car from being able to back out. I did see these in the parking lot but never had to deal with them.

We stayed at a hotel in Collioure that used them but management took care of lowering the bar in the morning before our departure. I never quite decided whether they were to keep your car from being stolen or to keep you from leaving before paying the bill :) I do know it is a way for the proprietor to "save" a spot for his clientele. When we checked in the owner came out and lowered the bar for us to pull into the parking spot. Perhaps the code "lowers" the bar to allow your car in?

2) When we stayed at L'Auberge St. Pierre, they had a private entrance off the ramparts that you needed a code for to gain entrance. We've stayed at other hotels where management wasn't present 24/7 and you had a code to be able to gain access at any hour...obviously this only works if you've already checked in, or if the room door code is the same as the entrance code.

Thanks again to those who have been helpful. We asked the hotel however they were so vague, just gave the code and nothing else. We will see soon!

I'm back and can now answer my own question for future help. We drove up close and were stopped by a person who gave us the same code the hotel had. It allowed us to park closer after entering the code in a key pad which opened the 'arm'. Later that evening when we left to have dinner, the person was gone however at that point we already had the code. IOW, if you approach the closer parking during the day, you can show your confirmation. If you arrive in the evening, best to have asked the hotel for the code in advance.

IMO, the internet and e-mail are flawed ways of communicating. There are so many ways to interpret brief comments that people quickly dash off. If I were to receive replies that push my buttons as negative, I would take a breath before reacting and try to assume the person meant well. It's better than getting into an internet p***ing contest.