Exporting to Excel

Hi,
Is it possible to set the precision of an excel cell through coldfusion? I have a coldfusion page which displays a rate formatted to 3 decimal places e.g. 0.048%. I then export it to excel - using <cffile>, but when I open the excel file the cell defaults to 2 decimal places 0.05%. How can I make excel display it as on the coldfusion page?
All help appreciated! thanks!