Hi Peter
At the Moment, you can't control those yourself. Only Airplane Devloper can include them into their code. Aerosoft will update the Airbus soon, and also FSLabs and maddog ar known to use them. I am not sure about PDMG.
Umberto told in another topic, that mabe there will be an option to set it in the GSX menu (or Aircraft.cfg). But that's not yet available. So at the moment, it does only work if your plane devloper implements it.