Excel Date Formatt Issue

I have a worksheet containing client data along with several dates(3 per column). About half of the dates are before 1900 so its not an issue, the others however, as you know, excel is storing them as a number, not a date, ex 39440 instead of 12/24/2007. My issue arises when I attempt to import this sheet in to Access. Access does not recognize the digits as a date, and will not import the data. Is there a workaround for this, or any way to keep Excel from storing the data as a number? Thanks for you help in advance!!!