Become a doctor, get a few years of practice to gain experience (the longer in practice, the better) so you know what the needs of doctors are in the care of patients and what their work life is like. As you are practicing, to back to school for a masters in healthcare administration. Then you will be well qualified to be a medical executive. I can tell you from experience that doctors are not likely to listen to you or respect you as an administrator if you don't know what its like to be one of them.
If you look at some of the large medical groups (think huge multispecialty groups like the Permanente Medical Groups), the administrations are all led by doctors who were in practice for years.