I have a Word document that uses fonts not available on my system. How can I globally replace these fonts? I've tried both Find/Replace (with formatting) and Tools / Options / OpenOffice / Fonts, but both of these only seem to support replacing one installed font with another -- typing the name of the missing font in manually doesn't work.
I believe you can do this using the following dialog available under the Tools -> Options pulldown menu.
This will replace the font Arial with Caladea, for example. I realize you said you tried this but these are the exact same directions as described here on Debian Wiki in this topic: SubstitutingCalibriAndCambriaFonts, specifically in this section.
The key thing you have to do is, after making a mapping such as this, you're required to restart LibreOffice. I would assume the same holds true for OpenOffice too.
NOTE: You'll need to type any names for fonts that are not installed when filling out the above dialog.