Basically I write this because beec's suggestions, although valid for some, will not work on others, and I'd like to diversify the methods of females of the world, to give shy little wusses like me a chance...!
Glimpse at the male brain for you: (at least my male brain)
As a shy clueless male I'd never even notice that gesture. I'd see it and think 'nah I must be kidding myself'. If I saw it again I'd look twice. A third time I'd be bashing myself on the head for a less subtle hint so I wouldn't have to doubt my stunted instincts. And I'd never make any sort of a move if there was even an inkling of doubt in what I'd just interpreted. Of course what it would take to make me make the first move I don't even know...!
Having said that if someone I barely knew came up to me and bluntly told me they liked me I'd probably hesitate, say thanks, and walk away and wonder what the hell just happened. (Mabe slap my own face if it deserved it)
Get to know him on the most basic level first and work from there without pushing the boundaries too hard. Try as hard as possible to feel normal and not shy, then you might just act normal enough to give a sensible impression. If he already likes you he won't care what you say, but if you're selling you're case then it's a different story.
If you're *really* shy them pm me, I want to meet other shy people and try to figure out the solution.
T.E.J.C
