not build, halt
Never mind, I had to copy the file manually to the source direction (%BaseDir%\Mount\Win8PESE\Source\BootWimSrc\Windows\System32\en-GB\) once it was mounted and before started to copy to the target. A tedious job if this has to be done every time one run the script.
To start with, I don't see why this file was not copied automatically as it is present in the DVD.