Please consult our FAQ section re: SIP. There's a dedicated thread to describe it and the values that may be used.
By all means, do try and inject CodecCommander from that folder, but if it does not load, you'll have to cache it from /L/E; this will have to be done manually through Terminal and after enabling Gatekeeper:
sudo spctl --master-enable
Reboot then copy the kext to /L/E
sudo cp -R <path>/CodecCommander.kext /L*/E*/
Authorise the kext through Security & Privacy PrefPane and reboot again.
You may then disable Gatekeeper again if you wish:
sudo spctl --master-disable