I wouldn't call Excel a database
. ;) Nevertheless this is very well possible.
Word has a mail merge feature. It allows you to take one source document and fill in some fields. Then merge it with a data source, like an Excel sheet, to get a resulting document that repeats the source document for each row in the sheet.
I'm pretty sure you must have used this feature, back then.
I'm using Word 2010, which has a separate ribbon dedicated to Mail Merge, and the wizards is docked to the side. I don't recall exactly in which menu mail merge could be found in Word 2003, but it should be fairly easy to find it now you know the name of the feature.
{edit} I see now that the tutorial I linked to, applies to Word 2003. :D