Does, your club have a drive-in of all captains together, men's, ladies', junior's, presidents', et al? Nightmare if you aren't confident at blasting the ball off the first tee with a sizeable audience!
My drive-in was ladies and a few gents, so not too bad, plus I knew all the gents, which made it easier for me. I appreciate it can be daunting if you have people you don't know watching your drive in, so here are a few thoughts that may help...
First is that everyone will be desperate for you to smash your drive down the middle - no-one is stood there wanting you to fluff your shot. Everyone is on your side - seriously. You can try the old tactic of picturing everyone naked, which can be a scary thought, especially if you dwell on some of the sights too long! If the worst happens and you fluff your shot in some way, just think, you have material for your speeches throughout the year - poking fun at yourself always gets people on your side.
You can practice your tee shot in advance, imagining the fairway lined with spectators. You can also try to be perhaps a little conservative with your swing. Don't try to knock the ball miles, concentrate on a solid swing, good rhythm, and don't worry about distance. That way you're hopefully not trying too hard on the day.

Have one or two trusted pals by you when you drive in. They'll keep you calm and relaxed until it's your turn. And do make sure you have a reliable photographer to capture every moment - photos are a priceless reminder of your year. My fellow men's Captain was a keen photographer, and he kindly offered his services. Did a great job, too! One thing you need to combat against is a well meaning pal who chops heads and feet off people! Have a contingency photographer at the very least.
Another thought is the ball you drive-in with. I don't mean whether you use a Titleist or a Commando (that'll be a test of the audience reading this!) but keeping the ball. My Captain offered to mount my ball for me perched (glued) on a tall tee, on a small block of wood, nicely polished. It has made a great memento that has pride of place in my cabinet at home.
It's common to have a competition to guess where your drive will finish, with people buying lolly sticks or plant labels, adding their name with a marker pen and then putting the ball in the part of the course where they predict your drive will finish. You can cap the amount the winner gets and perhaps have the balance as a starter for your chosen charity of the year. Just a thought.
And after the drive-in? Well, a brew and a piece of cake or a pasty always goes down well, or wine or.... whatever. Share what your club does to help spread ideas around!