Dear David,
You could use the csvread() and csvwrite() functions as in the example on the Samples page (it should be #6 at the moment).
If you are running the script on a Windows computer, you could use the Excel functions. You can find them in the Function Reference by clicking "Functions" in the script editor window, and then typing the word "Excel" in the Search box to filter the results. The Excel functions all start with "xl_," for example xl_create() creates a new OLE automation object, and xl_set() assigns a value to a cell or range in an Excel workbook.
Best regards,
Paul.