Ok, I'm sorry to trouble you.
We need exported file to find out which encoding their file is. We asked them, but their answer wasn't clear.
They said they couldn't convert by their side and asked us to convert by our side. But one file is in UTF. If they can convert to UTF-8 by their side, of course it's better. Poy san and Nammon san talked this matter to J compile so many times, but it couldn't be solved.
That was a reason that we decided to convert ourselves. They said their encoding is ANSI. So that we need ANSI file, IF THEY REALLY DIDN'T FINISH CONVERT SYSTEM.