Hi Lee,
The CSV file is just a txt file. You can open it by notepad.exe. So if we want to save the file with Unicode data, we should set the encoding of IO stream to Unicode. For example:
System.IO.StreamWriter sw = new System.IO.StreamWriter(fs, System.Text.Encoding.Unicode);
For more detailed information and sample code please access this link:
How to transfer data to an Excel workbook by using Visual C# 2005 or Visual C# .NET
http://support.microsoft.com/kb/306023
Sincerely,
Benson Yu
Microsoft Online Community Support
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