Combining duplicates via appending multiple lines of text columns

[chris.hinkelman]

I'm cleaning up a gigantic (20000+) Excel list of a salesperson's contacts with 20+ columns of info about the contact, and while it has a lot of duplicate people in it, they often have new information in the row that would be lost if I just removed duplicates. I'd like to be able to merge duplicate rows (using full name as a primary key) but still keep unique data and either tack it on the end of the row or ideally, throw it in an Email2, Comment2, Phone2, etc. field so it's easier to read. I've poked at conditional statements, but the 20+ columns is making that prospect a bit overwhelming, and mail merge in Word has been less than successful. Any ideas for a straightforward solution?

[#2]

But what if the "duplicate" row actually contains information that supersedes the existing information, like a change in address?

[#3]

Considering this is for a brand new Sales Rep who has no way of knowing which is the new address and which is the old (due to lack of timestamp), I'd like to find a way to save both.

[#4]

I think I would prefer to keep all records then and just sort them on firstname plus last name. That way you get all address information of one person close to each other so you can quickly compare them. Seems to me to be easier than having to scroll across columns?