I don't know the intracicies of it all but there are DVB-C cards with a CI module and ProgDVB which can be an option. As I said I don't know the intracicies of how ntl recognise what device can use the network or not but I'm guessing you would have to clone the MAC address of the STB to your DVB-C card for it to work with the CAM on the network. Don't quote me on any of that though