You can either first combine the NC files into one, as described in http://quantumwise.com/forum/index.php?topic=2128.msg10072, or just incorporate that in the LDOS plot script, like
...
lddos_list = nlread('lddos0.nc', LocalDeviceDensityOfStates)
lddos_list += nlread('lddos1.nc', LocalDeviceDensityOfStates)
lddos_list += nlread('lddos2.nc', LocalDeviceDensityOfStates)
lddos_list += nlread('lddos3.nc', LocalDeviceDensityOfStates)
...
Just do a "print energies" also, somewhere later in the script, to make sure the order of the data is correct.