skiing is not like running nor like lifting weights. it falls in between anaerobic and aerobic exercise. the only excersise that are going to work the whole upper leg all the way down to your knee, the same way skiing would, is Wall Sits. nothing will work the lower leg and foot like skiing would, so just do calf raise and jumprope.
really slow body weight squats might work. use a box or a bench to make sure your going low enough. explode up the instant your butt hits the bench.
also a very good excersise thats not too boring is too sit in a "rolly" chair with wheels. use your hamstrings(back of your leg) to pull yourself around the the room in figure 8s. once they get tired, than use your quads( front of legs) to push yourself around the room in figure 8s. repeat as much as possible to get wayyyy past the first sign of sornes... depending on how fit your are. make sure to go both clockwise and counter clockwise with this one