>Thank you. I think, it is the best solution among the answers.
>But if we consider how long it take each of us to find the answer of 'how to do it in Excel', I would say Excel is useful, not great. But this forum and our community is REALLY GREAT!
>

Oh, yes. I think your "expression" is more real. Since I'm not
a naive English speaker. Thanks for your comments.

Chris Lee