I've got two separate workbooks. Each workbook contains unique columns except
for one, which is a "key" column, or an id field.
Example: I have a client # column in both workbooks. In the first workbook,
I also have first name and last name columns. In the second column, I have
phone number and address columns. How do I merge the two workbooks into one
so that for each client # I have their first name, last name, phone number,
and address.