Labeling unique pages with unique identifiers (name/ID number)

I have one document with 144 pages.  Each page is unique and numbered (1, 2, 3, etc), and I want to label each of those pages with a set of First Name, Last Name, and ID number which correlate to the numbers on the page.  For example, the top of the document will say "Case #1" which correlates to John Smith, ID#22201, then second page will have "Case #2" which correlates to Jane Austen, ID#22202, etc.  The document is not the same, meaning everything else on the page is different text, so I just want to "label" each page with the unique identifiers.  Possible in the footer of the page as the text is crowding.  Not sure if I need to splice each document out individually?  This is something that I need to do every few months with different identifiers (different names that correlate to the same case #s, so I realize I can do this manually - copy and paste the information on each page, but looking for a long term solution.  I tried mail merge, but I am limited in my understanding, and I believe it has to be the same document that can "import" the identifiers onto the same text.  Thoughts?

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