Hello mouser999,
Use a trusted keyfinder utility (such as the Magical Jellybean Keyfinder or Belarc Advisor) to get the product key.
Download Office as appropriate from the links in this post:
http://social.answers.microsoft.com/Forums/en-US/officeinstall/thread/ac67aa2f-dc1c-46f4-8b1d-ca00b3f02a18
It would be to your advantage to locate and safeguard your Office product for future use.