This table:

http://mythtv.org/pipermail/mythtv-users/attachments/20031125/ad787d1d/Cable_casema_DenHaag.obj

Can be converted to SQL using:

perl -we 'while(<>){ /^(.+?)\s+[\d\-\+]+\s+[\d\-\+]+\s+([\w\d]+)\s+([\d\-]+)$/ && do {print "UPDATE channel set name=\"$1\",callsign=\"$1\" where channum = \"$2\";\n"} }' > myth.sql


(just paste the table into the command box where you executed perl)

You can now feed myth.sql to your mythtv mysql instance, and your channel names will be set correctly.