I have an Excel table with rows of monthly data, and one of my fields is the Purchasing Managers Index (PMI). I want to show in a clear and concise manner that this column's data comes from https://research.stlouisfed.org/fred2/series/NAPM. Ideally I would have the column labeled "PMI [source]" with "source" being a hyperlink to the site. However, that's not going to work in Excel because you can't hyperlink only part of a cell. I also don't want to rename the column to "PMI (source: https://research.stlouisfed.org/fred2/series/NAPM)" and include the full hyperlink in the text of the column header, because that would make the column header way too long. What else can I do?