hiz_child,
Here's a question for you, where is this guy going? A mission trip or something? I think a great way to at least let him know you're thinking about him is to tell him that you'll be praying for him, etc.. If this guy is pretty shy and it *seems* like there is a fair chance he likes you, then, I bet he does. I'm fairly shy myself, and I've been in a few situations in my life where there were shy girls who liked me and I doubted myself so much that despite all of the obvious signs they would give, I still was too afraid to do anything about it. Like I said, try to start up a conversation with him about where he's going, what he'll be doing, etc... and tell him you'll be praying for him, and do! Ask God what His will is for your relationship to this guy, and ask Him for guidance in this.
Also, don't worry about rejection. Be as friendly as possible, in that, you can show him how much you care by asking him about him going away and that you'll be thinking of him, etc... which will give subtle hints. If he still doesn't get it, be honest with him. Let him know that you are interested in getting to know him a bit more as friends. You don't have to blurt out that you've had a crush on him for awhile or what have you. Just be honest and friendly with him.