Hi Laszlo,
There is no function of ClassEDisplay yet that changes the display mode. Also, the parameters to ClassEDisplay::Open are internal EDGELIB objects, you can't typecast window handles or other Win32 objects to the function unfortunately.
The best way to currently handle this is to make your main class friend of ClassEdge. Then pass the instance and windowstyle objects of the ClassEdge to ClassEDisplay::Open.