How to work for Microsoft?

Im currently in college studying I.T practitioners level 3 (a-level) and would like to study for a HNC (higher national certificate) after and then progress onto a degree. Is there any way I can work for microsoft doing a Specialist job? Ideally I would like to get into I.T security with them and be quite a higher up worker. Please give information on what you think would be the best courses to take after my A-levels or how to go into a certain path. Thanks