All the solutions are so good.
Honestly the question is fairly easy to give a solution. But here to this question I have some comments. In my opinion, the key of doing such job is of how fast you can do it. without cosidering that, the simulation will become ugly. Sometimes, you may think of that: don't use macro to repeat algorithm but to repeat text. What i mean is, 1*1000 = 1+1+...+1 (1000). Using macro to loop, sometimes is simliar to adding the 1000's 1 but may hinder you from getting a better way to achieve the goal.
Please read it. JingJu
http://blog.sina.com.cn/s/blog_a3a926360101h2x8.html