I'm attempting to streamline a process for renaming PDF documents received from multiple vendors to conform to a specification provided by an EMR vendor for ingestion. Things like Document ID, Document Type, Date of Service, Account Number, MRN, etc. all must be included in the filename at defined offsets and lengths. Most of the required values can be extracted from the inbound file's name and the few remaining are static values that would be the same (or handled via a lookup table based on source) for all documents.