Duplicate rows, delete columns w/same data, combine columns w/unique data, Mac Excel 2011

Hello,
I am new to this forum, but I have spent a lot of time here and elsewhere trying to find a way to manage this project. I'm not familiar with VB scripts, so I'm having a hard time modifying other examples to my own needs.
I have combined records from 4 different sources into a monster, um, master list of 22K rows and dozens of columns, including many duplicates of column cells. I want to delete the column cells that have identical data, and combine the column cells that have unique data.
I've sorted by last name, first name and used a script to identify duplicates. Next I'll have to match last name, email. to find further dupes. I expect there about 8K unique records when this is done.
For instance (and I'm going to try to attach a sample XLS file)
First Name | Middle Name | Last Name | Programs
Col | | Amb |
Col | | Amb |
Je | | Ambur |
Je | | Ambur |
Mar | | Amst |
Mar | C. | Amst |
Mar | C. | Amst | 08C
Mar | C. | Amst | events

So in this sample set, I'd like the results to look like this:
Col | | Amb |
Je | | Ambur |
Mar | C. | Amst | 08C, events

I apologize if I'm unclear and will happily provide any additional information. Thanks for any help you can provide on this monster project!
Kind regards,
Margaret