Outlook 2003 new message to: field

When creating a new message and clicking on to: to select the people you are sending to, or even when just starting to type the person’s name in the to: field is there a way to get it to look at last names when it looks for possible matches for you to choose from? We have found that we have to start typing the person’s first name in order to get a match and since we are not always sure of the person’s first name we would like to be able start entering a last name and get possible matches to come up. Is there a way to do this?