Thats correct, in order to watch ComHem's HD channels you will need a CI+ module.
I might be misstaken, but i thought there was some PC hardware that supports CI+ modules?and if there is it should be possible to connect the device to your TVheadend.
Found this card that might be a solution?
https://www.tbsdtv.com/products/tbs6...l-ci-pcie.html
There is also miraclebox's and VU boxes that support CI+ modules and has CI slots you that you slide the Comhem CI+ cam module in to on the box.
Might have to use some thirdparty firmware to make this work.