Hello,
I need help figuring out how to do this, or if it's possible.
My spreadsheet has multiple "sessions" by date and each has three columns: a name, their organization, and a column where we want to display an "R" if they are a repeat participant. Each new session is entered to the right of the last. The names are in every third column. Like so:

name company R
name company
name company
name company R



Is it possible to search through the whole document to find repeating names, and then display an "R" in every third column if they are a repeat participant?

Thanks in advance!