ISO-8859-1 charset support?

When naming an excel sheet, I need support for the danish letters: ?, ?, ?

I have no problem populating the cells in the sheet with the letters. Consider my code:
**************************************************
string fileName = "M?lepunktoversigt";
excelApplication.Save(fileName, SaveType.OpenInBrowser, FileFormatType.Excel97, HttpContext.Current.Response);
**************************************************
The sheet that opens is named "M?ï¿¥lepunktsoversigt" instead of "M?lepunktsoversigt".



I have tried the following:
**************************************************
byte[] bFileName =null;
bFileName = Encoding.Default.GetBytes(fileName);
fileName = Encoding.ASCII.GetString(bFileName);
**************************************************
which makes fileName = "Melepunktsoversigt"

Do you have an idea to solve this?

Please check

for reference.

If you use OpenInExcel or OpenInBrowser option, you can only use ASCII characters in file names. You can try to save the file on disk of your server and provide a link to your users.