coby, rather than worrying whether you're presenting yourself with subtlety, i would encourage you to forget about the overall impression and just be sincere in your intentions and feelings about the guy. people deserve the genuine expression of your feelings, rather than a contrived message.
also, instead of putting him on the spot, you'll express your interest in a far more effective, and authentic way by engaging him using the means of contact/relationship you currently have. the following actions are all pretty clear ways of expressing genuine interest:
+taking the onus of initiating conversation, rather than simply waiting for him to engage with you.
+like a tennis match, show reciprocity in actions and effort. don't make him take all the effort, and you shouldn't be the one who is always "serving", when he isn't playing back.
+communicate with him in a more active and present way. for example, ask him questions about himself and when he shares about himself, be an attentive listener. one of the most effective things you can do to show interest and care for a person is simply by giving them your undivided attention--ignore your phone, stop scanning the room, don't fidget with every distraction. you send a mixed message when you ask someone a question or show interest in them and then acknowledge every single person or distraction that comes your way when he is talking to you.
further, as a side-note: i have learned that few people are regularly on the receiving end of listening that says, "there's nothing happening in my world that matters more than listening to you and hearing what you have to say". it's pretty powerful. it's also a sincere form of respect and appreciation. it's a vitally important thing to do for people who matter in your life.
+finally, one thing i've seen men especially respond to is enthusiasm. a lot of folks' overall affect is nearly identical whether they are happy, perturbed, or bored. if you are more reserved in nature, i'd make an effort to express some enthusiasm IF you are feeling enthusiastic about someone. and if you like a guy, geez, make sure that he can tell you're happy to see him rather conveying wild indifference.
after you've gone to the extent of making clear your interest in spending time with him, and that you enjoy his company through actually ENJOYING his company, i'd leave the ball in his court. plenty of women like to pursue men, and if that works for them, that's great. i personally have never found it to be necessary, worthwhile, or anything short of counter-intuitive.