Alex is correct, but as you have to export to csv, you can give the users this advice when opening the csv files:

  1. Save the exported file as a csv
  2. Open Excel
  3. Import the data using Data–>Import External Data –> Import Data
  4. Select the file type of “csv” and browse to your file
  5. In the import wizard change the File_Origin to “65001 UTF” (or choose correct language character identifier)
  6. Change the Delimiter to comma
  7. Select where to import to and Finish

This way the special characters should show correctly.