I am trying to create a formula/automation/script that looks at a field of images (All PDF Files), and takes the field that is named in the file "RULES", and add this file only to another field called RULES.
It sounds like you want to move one attachment from one attachment field to another, based on the name of the attachment.
You cannot do this with formulas. Formulas cannot move attachments from one field to another.
You can do this with scripting. The scripting documentation has info on how to read and write record data. What is your level of scripting experience? If you are new to scripting, how interested are you in learning scripting?
Is there more than one PDF file with the name "RULES" in the attachment field? If there is only one, then a combination of Formula and Automation will do. (Two automations are needed at a time). If more than one, Script is needed.
