I get the impression you are describing a system like that on the Spitfire - a picture says a thousand words, and I am sad enough to have a photo (taken when I bought the boat, so I could reassemble it!). I have found out since that the outhaul (yellow rope) should go through the foremost hole, not the rear one.
It is a really simple system - the outhaul emerges from the boom, goes through the eyelet in the sail and a knot in the end is slotted in a groove at the rear end of the boom. - the blue string hanging from the mainsail has a quick release hook / caribiner, which connects to the top mainsheet block.
Both the outhaul and the mainsheet can be dis/connected very quickly.
