One time use code for website

We have a website that we are building, and we would like to set up a database with lots of different codes in it. (around 700 or so) When a person uses one of these codes, they would be allowed into a secured area of the website, but it would be only a one time use coupon. Is this possible?

The (very simple) website is already done, we just need for someone to be able to click a link and enter a one time use code to get into the secured area. Pop up box, embedded area, or whatever is easiest.