I think that if you have a few inches of cable sticking out, you maybe can cobble something together to make it work. You get a cable clamp at a hardware store. You might even use just a knot in the end of the cable, tying a cord to the knot. Leave enough space in the existing cable so it can get pulled into the sheath when you accelerate, and attach a heavy cord or appropriate cable to link to the pulley. You'd have to adjust your cord to approximate the effect of a properly installed cable. That is, just a small amount of slack when the foot is not pressing on the pedal.

I never did this - but if it happened to me and I was away from home, I'd have a look to see if it could be done.