Hello, I'm working on creating an "opportunity sheet" in Excel. I have 9 instructors (teachers) and 105 topics to teach. What I'd like to do is to add all the topics in a spreadsheet and give them a quick way to see courses they haven't taught in the past.

So, there is a "sign-up" drop down list for topics to assign an instructor to, and I want them to be able to run a macro (or something) to look up previous courses (same spreadsheet but different tabs) and only show the courses they have NOT signed up for in the past so they can pick stuff they haven't yet taught. I realize it's easy enough on paper to figure out, but if I can make it easier for them to see their choices, they'll expand their topics.

Thanks!