Are you asking if you can major in something besides Biology and still go to medical school?
If so, the answer is an unequivocal Yes. You can always take classes beyond those required for your bachelors degree. Many medical schools require that you have taken specific coursework, though not all. And ask other posters said, you will need to know that material for the MCAT anyhow. Even as Biology major, you have to ensure you take the required labs, chemistries, etc. that may not be mandatory for a degree in biology. Majoring in something besides a pre-med science may also help make you a more well rounded person, give you some possible padding in your GPA, expose you to non-science people, etc.
If you're asking if a computer science degree will include the courses needed for medical school, it's highly unlikely. I'm not aware of a basic computer science engineering major that would include the amount of chemistry and biology needed for MCAT and pre-requisites.
You can major in anything and also take the courses needed for medical school.