I need help, and I'm lost!

I have a simple count-as-you click button form, and this is what I want to do with it:

Click the button (however many times) to get the sets of numerical data. Take those numbers into a cookie, and be able to add/subtract to each number as i use the form again; and update the cookie. I need a way to be able to do this multiple if not an infinite number of times!

Is this even possible?

Help!