I'm trying to setup an automated way to send computed bills to a list of
people in an organization (about 300).
We collect data (water usage) and use Excel to compute the bill based on
usage (current reading - previous times rate).
Each row is for a particular meter, and has a number.
We have a seperate list of people, with mailing addresses. Some people will
have more than one meter (we could make it one-to-one by creating duplicate
entries for these people as there are so few).

I'd like a way to combine the address list and the excel data and generate
bills - sounds like a mail merge but with two data sources.

Presumably Access could do this, but I don't have any experience there and I
want people after me to be able to understand what I've done.

Anyways, I'm open to suggestings. The addresses do not have to be in
Outlook, but it is convenient since Outlook Address Book does a good job at
managing this data.