If you want 'Mar-13' to remain 'Mar-13', you would probably need to use either:
• Excel's Data>Get External Data>From Text function and set the comma delimiter then format the affected column as text; or
• a macro to convert the date back to a string after opening in Excel.
Note that you'll need to do this every time you open the csv file.

The alternative is to use a macro to read the csv file into Excel one line at a time and output each affected field in text format. This would be a much slower process, though, and would still need to be done every time you open the csv file.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]