How add playlist Total duration?

Hi. Sorry for bad english
Aeon NOX 6.0.0. Windows
In Confluence skin and some others Current playlist have Total duration of all elements in playlist. But Aeon NOX hasn’t it. I try to googling that question, try to find this attribute in xml and add to Aeon, but fail.
Maybe someone know how add total duration attribute in current playlist window? Script maybe or xml – i dont know. Please Thx