Hi
The qemf seems able to only rendering of EMF not generating it.

What is the data you want to put in the emf file ?

Qt has http://doc.qt.io/qt-5/qpicture.html#details
that works like WMF but its not same (file) format at all.

However, its pretty simle to generate WMF/EMF from windows API.
(CreateEnhMetaFile)