Well 2 ways come to mind.
1. Place the winzone in the desired location. Set the name of the winzone in the "ifused" field of the switch. Then change the appear/start script of the winzone to an appear if activate script. This way you can put the winzone wherever you want so the player will have to flip the switch then travel or have it spawn were the switch is for instant win.
2. Copy the switches main script and add the action "win" (dont forget the comma to seperate ,)at the point after the switch is flipped. Then set the switch's "isobjective" field to 1 (any besides 0). This way you win instantly, and its easier to replicate in future levels.
As always, Game on! -2S!K Productions