The set up is much like I set up in 1999. See Davis Creek Elementary.
http://daviscreek.cabe.k12.wv.us/snowskatingpicture2.html

The picture demonstrates the placement of the gears and magnets to reproduce this project.
Notice the gear train.
The entire top beams rotate unless there is friction stopping the rotational motion
at which point the large gear at the top will go around.
The large gear is a place for the magnet to be attached.
There is a magnet attached to the ski.
Magnetic attraction is what holds the skater to the mechanisms beneath the glass.
  The mechanism below the skating rink works with
   gears and magnets to "guide" the skater.  You will program the RCX brick to swirl the skater.

Example program on http://SENSORSCITY.marshall.edu/CITY/pages/vi/
The motor for the skier is on port C.
You may multi task and also run Scenario I andScenario II
at the same time.