Try the attached. Simply save both files to the same folder. Note the extra column in the worksheet to calculate the expiry dates.
Of course, you may not want the shading I've used for the tables. The output format, including the shading, is controlled by field switches. To see the field codes and switches, press Alt-F9. For an overview of what they do and how they're used, see:
http://office.microsoft.com/en-us/wo...010260104.aspx. That link refers to a 'Table AutoFormat dialog box', which you can access via Insert|Quick Parts|Field>DataBase.