I don't know anything about the lookup function but I suspect it is the
answer to my question.

Here is my problem:
I have a list of 5000 student names and addresses (file #1). I have another
list of addresses and distances from a school (file #2). My goal is to be
able to somehow link file #1 to file #2 and "lookup" the distance by matching
up the addresses.

How can I do this?