You can easily remove the tool end connector on the festool hose and the vacuum end connector on the mirka hose, look for youtube videos if you don't know how. Then and only then will you be able to see if the spiral from the raw hose can slip over the spiral of the other. Electrical tape is a good way of taping them up without long term residue.
I've had a Ceros for 5 years and added the hose extension to double the length which required this technique.