Customizing FF Print-to-File Options

[RMOP]

I'd like Print-to-File within FireFox to always default to .PDF, and to also default to a specified output directory. I don'm mind specifying a filename. In my case, I want the output directory to be on a shared NTFS drive. cups-pdf does NOT seem to support output to NTFS drives, AFAIK. I tried already just to see.

Suggestions?

Thanks.