I would suggest creating the certificate in Publisher - exporting it to Word - and then setting it up as a mail merge template to your Excel name database.
If you created the merge to a particular place (ie. the Desktop) before you save it as a template - all you would need to do in the future is create the Excel file and drop it on the desktop before you open the Template and it will automatically pick up the data when it opens!!
Also, please remember that there are thousands of great free templates on
www.microsoftoffice.com. You can spend ages creating one from scratch - far easier to get an idea, or initial design.