Unlike the wiki suggestion, I used dvb-utils to scan for my dvb-s channels (much like outlined for dvb-t)
sudo scan -o vdr /usr/share/doc/dvb-utils/examples/scan/dvb-s/Astra-28.2E > channels.conf
I should imagine that there are scripts in dvb-utils to scan for dvb-c in a similar manner.
Check /usr/share/doc/dvb-utils/examples/scan to see if there is a folder called dvb-c (obviously you must first sudo apt-get install dvb-utils). If there is, see what files are contained there.