@Drbohlav: Here is an example.
I am using the pyproj python package to project a point in the UTM zone of the project to the target projection. This library is a bit flexible with the input definition so Iām both using the ESPG:5514 as a string and the proj4 string.
ProjectPoint.dyn (14.8 KB)
Please follow up if you have any issues with applying this method 
We use proj4 extensively internally to make these projections.