Clonac is Diclofenac which is a non-steroidal anti inflammatory. You can certainly take this in combination to paracetamol and codeine.
The combination of these medications can help alleviate the pain you may have, but it is always important that the pain is investigated thoroughly and managed if possible.
With any non-steroidal anti inflammatory, it's important to take with food as it can upset your stomach and may cause stomach ulcers.
All the best.