How do I identify past participants in Excel DB?

I have an excel file containing registration information for individuals enrolled in specific classes. A given row is the information for one registration, and the columns give information for Program Name, Iteration Name, Contact Name, Grand Total, etc. If someone takes multiple classes, their name will show up in multiple rows.

It's easy to get a list of people who participated in a given program. What I want is, for each person who took program X, list out what other programs they've taken in addition to program X.

For example, say I'm making a report about the September 1-3 Corporate Finance class (Program Name = "Corporate Finance", Iteration Name = "September 1-3") and I know that John Doe was in the class. If John Doe was also in the May 10-12 Leadership course, I want that to information to show up alongside his name in my participants report.

I've tried using pivot tables but I'm a bit of a noob at it and got lost. Can someone lend some fresh eyes to this problem?

Thanks.

A sample file would allow us to see if there's an easy answer.

I've attached an example file that should make this clearer. Pulling this stuff individually is easy - I can just search for the individual registrant in our database and a list of all their program registrations shows up. But for programs where 100+ people have signed up that's very tedious, and I'm hoping Excel can fix the problem because that's what people in my office are used to using.

It also fits into a larger post-program analysis report I'm making that breaks down registrants by demographic and other factors. That part is easy - I just want to incorporate this "past participants" list into the same document since it's based on the same data.

Bump. Is it clear what I'm asking? Basically I want a way to filter Pivot reports based on whether a contact has been in a particular iteration of a program without removing the information about all other programs they participated in.