Don't do that, just find the emails of doctors through your school's website and email them directly. Wait 1 week if no response then call their secretaries and ask about shadowing if you're really committed to that one guy. When you're interacting with these guys you have to think about the fact that they might become your mentors in the long-term, so their ability to effectively and efficiently communicate with you can be exceedingly important. You want someone who's a full professor so they have a certain level of clout, but not someone who's on the door to retirement because they will have less grinding that they need you for. Your biggest role for these guys is basically gopher, its like going golfing with your dad when you're 12, you're going to caddy for the most part, but every once in a while they're gonna need a 4th and you get to play aka you get a paper or get to go to a conference. Sadly/truthfully, you have very little to offer them besides a worker that can do the same work as any other medical student, so really just smile and do whatever they want you to do. Also, make the ancillary staff like you and it'll help.
Also, one thing you need to learn early is that the more levels of bureaucracy you have to get through in order to get what you want, the longer something will take and the lower the chance you actually get it. Most of the time I have had a problem in school just showing up at the office of the person who can fix the problem works better than innumerable calls/emails. These people are busy.