I'm certain this can be done, but since I've not yet done so I'm not sure how to proceed.
In Preferences -> Editing -> Shortcuts -> Document and Window I see 'buffer-export' has two chords: Ctrl-H (in plain font) and Ctrl-X H (in boldface font). Why? I don't know, but that's what's there. What I would like to do is assign Ctrl-X H to File -> Export -> pdflinux (or buffer-export-pdflinux). When I highlight 'buffer-export' and select the Modify button I'm not seeing a way to add the pdflinux as the default export format. A cluestick will help. Rich