I have a two dimensional array something like this:
We'll call that sheet "Requirements".
I have second sheet where the names are validated by the list on "Requirements". We'll call this second sheet "Attendance".
On the "Attendance" Sheet, I want to be able to select names and show the total number of vegetarians, for example.
If I selected "jeff", "ceri", "angus" and "lisa" on the "Attendance" sheet, the result should be 2.
How do I associate the names on the "Attendance" sheet with counted and totaled values from the table on the "Requirements" sheet?