Fitting points in an equation

I am trying to do an optimization problem where I will input the points and I have to find the equation of the curve which fits into it. I am using genetic algorithm to find the equation. I am giving the criteria that the distance of the point from the equation to be minimum. I am able to get a curve that doesnt fit the equation exactly, but has the least error. Is there any other method to find the near exact curve?

Thanks all.

[John Petersen]

Do you know the form of the equation for the curve? How many parameters define it? This type of information will help determine a good method to use.