QUE is the Spanish and French word for “that”. It does not exist in the Words With Friends, Scrabble, Merriam-Webster, Roget’s, or SOWPODS word lists. Dictionary.com lists “’que” as a shortened form of “barbecue” from California slang, but since that requires an apostrophe it is not valid in any word game. Random House list “Que.” as a three-letter abbreviation for Quebec, but since place names are proper nouns, it is not a valid play. Wiktionary lists it as Anglo-Norman or Middle English and is thus not valid.
DOUX though of French origin, refers to the sweetness of champagne, a beverage exported all over the world, so DOUX would be valid in a Scrabble game in any language in a country where champagne is exported to.
Similarly ROUX though of French origin, refers to a base used to make gravy, so ROUX would be valid in a Scrabble game in any language in a country where people make gravy.
If you have a valid word to add you can always make a suggestion at the Zenga Help Desk, but in this case I would say you're out of luck.