Selection by Bookmark

When creating a multi-document PDF you will often specify bookmarks that are to be inserted into the PDF. See _document.bookmark  Using that script function in your forms when you create the combined PDF, you can insert bookmarks of chosen names and values as applicable. Then, rather than having to know the ordinal number of a document you could select/extract by bookmark value.

DO PDFExtract -in multiDoc.pdf -docs "SalesRep=Sam"