Thanks for all the answers! I came up with one solution, with AFRLme help, and totally forgot to check the forum for other answers 

@sebastian Thanks for your version, as with it I modified first solution I had, to work in 4.2.5 Visionaire editor.
 function onTextStart(text)
 if text:getLink(VTextOwner):isEmpty() then
  if game.StandardLanguage:getName() == "English" then 
   text:setValue(VTextFont, Fonts["default_font"]) 
  elseif game.StandardLanguage:getName() == "Chinese" then
   text:setValue(VTextFont, Fonts["chinese_font"])
  end
 end
end
registerEventHandler("textStarted", "onTextStart")
 That is a version of lua that eventually worked.
But still, a different problem appeared. 
How can i change Action text font text when i change game language? Because now, the dialogues display ok with language change (wrong font selected was crashing the game before), but when the cursor is over an object, the chinese text that is in the "Object name field" crashes the game (unable to display i suppose).