CSV files can easily be imported by excel. You can then
programmatically alter the field that is being incorrectly formatted as
a date. I am guessing the field is some kind of number (remember dates
are stored as the number of days (whole numbers) and hours, minutes
etc... (fractions of numbers) from a given date in time (1900 or so) in
excel so sometimes numbers get formatted incorrectly - it doesn't mean
the data has been corrupted in any way so changing the formatting
should do the trick.