what you call a "PCMCIA Conax adapter" is called a CAM. A CAM can only work when inserted into a CI slot. Although they are the same formfactor as PCMCIA cards, your PCMCIA port on your laptop is not a CI slot. So you can not use that.
If you want to use your smartcard to access your encrypted channels via tvheadend you need to setup a "cardserver". In order for that "cardserver" to be able to access your smartcard you need a smartcard reader (for example a Smargo smartcard reader).
There are various software programs that you can use to setup a cardserver. The most common are newcs, cccam and oscam. OSCam is opensource and there are some guides how to set it up (also in combination with tvheadend)
I hope this helps you started.
Hein
