Checking in without a confirmation number?

I am taking a trip to Tokyo with a group from my school over winter break, and I'm having trouble getting my confirmation number for my ticket. The tickets were booked through a travel agency but I don't know details beyond that. It wouldn't be a problem except that I will be checking in separately from the rest of the group and meeting them at an airport closer to home where they are having a layover (does that make sense?). I've been emailing the supervising professor who has all of the paperwork, but he hasn't gotten back to me and we leave in less than a week, so I'm getting antsy. The international help line for Continental is being unhelpful as well, along with the website. My question is, if worst comes to worst and I can't get a confirmation code to check in, is there another way I can get a boarding pass at the counter? My passport information should be on file and I know my flight itinerary. Thankfully I won't be checking any bags, but this is a once-in-a-lifetime opportunity of a trip and I would hate to miss it because of stupid bureaucracy.