Like @Steven P "Generally I save to the same folder as the CAD file"
In the attached file is a plot a range of pdf's a DCL pops up for the range then the plots are done. In the code you will see a command Mk-dir that is used to make a PDF directory. I think we have discussed previously about making menu's as the simplest way of click on a choice and it happens. See image above, keep adding options for users, they don't need to worry about appload or (load."????") I had 8 users, our menu was on a server so would auto update for end users.
You will need to change the code to suit your title block and pdf settings have a go. It is set up for title block at 0,0. It is possible to have one lisp but it uses different variables for different output devices and title blocks. A version I have for a client looks at title block name and sets the correct plot size settings.
Come back if have a problem, you have my Email ?
plotA3Pdfrange.lsp
Multi GETVALS.lsp