You cannot plug your laptop into your car for anything other than power. At least not in stock form. There are several ways to change the stock fuel injection mappings, if that is what you mean by 'tuning'.
Check out this site for more info: http://www.phearable.net/tech/efibeginnerguide.html
Your ECU does not contain any kind of port that a generic computer will connect to and interact with. Instead, you can modify portions of your ECU (depending on how much money you want to spend) that will allow you to change the fuel injection mappings. You can also splice in some kind of intermediary device between your sensors and the ECU in order to 'trick' the ECU into thinking it is entering a different state so that it may produce the desired output.
While these are all ways to change your stock mapping, none of them are acutally recommended for shade-tree mechanics, as the 'tuning' is really difficult to perform without a dyno. The pre-programmed maps typically available are usually created by speed shops with dyno equipment.
