Here are the 3 solutions I have got:
I) With OpenOffice you can convert any ms excel format to any excel format (CSV too) and you can choose the character encoding, delimiter characters, etc for example utf-8 too.
- Open xls file in openoffice
 
- File/Save as
 
- Choose the output format (CSV)
 
- Click on save
 
- A dialog appears, choose character encoding, delimiter character, and the other.
 
II) You can do it with ms office >= 2010 too:
III) Or if you have notepad++ you can convert the character encoding of the 'wrong' character encoded CSV file.