For users not using the PortableApps.com Platform, you can add additional fonts to the OpenOfficePortable\Data\fonts folder for use with OpenOffice here. (Do not add fonts to the OpenOfficePortable\App\DefaultData\fonts folder or to the OpenOfficePortable\App\openoffice\Basis\share\fonts\truetype folder)

Note that any fonts placed here will be available to other applications.  If any other apps (including local apps) are making use of these fonts and don't properly stop when OpenOffice Portable is closed, you may be unable to eject your drive until you close those apps.