I can successfully manipulate fileds on a master slide of a PPTX document with this code:
$TBS->PlugIn(OPENTBS_SELECT_SLIDE, '1', true); // select master slide
$TBS->MergeField('abk', 'ainfo', true); // merge field 'abk.ainfo'
However, I fail trying to do the same with an ODG file that is just the PPTX file saved in a different format through LibreOffice.
Any clues?