How to explain my low high school grades in my statement of purpose?

I am an Indian and applyin for masters in Computer Science, Fall 2010 in some US universities. During high school, my science and maths marks were very low but I got a 98/100 in Computers. But I did exceptionally well in my undergraduate course in CS. I even aced the class(Rank 1) for 2 semesters. I also won the 2nd prize in Intel Theading Champion.

The point I am trying to make is that my academic results were ‘awesome’ after high school. So in the Statement of Purpose, should I just say that I got too involved with computers during those years and sort of ignored other subjects (TRUTH) or make something up.

Thanks for the help