The problem I'm having is that a regular cable release doesn't screw in to the "Quicksocket" thingy. I have googled and searched various forums without discovering what I need to get a cable release in there. I would greatly appreciate your help.
There's a little metal "bullet" that your cable threads into and then that inserts into the socket. The red disk on the cable socket is a quick release so you can remove the cable (with bullet attached) for storing the lens/lensboard.
Call Marflex and order a couple. (I don't have their number handy - maybe someone can provide that ...) Oh, I see you are in Sweden, call your local Linhof supplier or perhaps the factory.
Alternately, get a Gepe flexible cable release extension and use it in place of the Linhof quick release system. It has a small nipple that will fit with a Linhof recessed board. You can order one from B&H, mpex.com, and the other usual places.
Old cloth covered cables from the 1930's also have very short nipples, and can be used. They were made to be left on folding cameras when closed, so they're really flexible.
Marcus - here is a photo of the "bullet" attachment for the end of the cable release. I have seen these referred to as "quick release nipple" or "cable release nipple". You could try a search on these names. I know of a store in Sydney that sells them right near where I work. Let me know if you want me to get you a price quote. Happy to send one to you if you have no luck in your hemisphere.