Ok, this is what you must do...
1.Place a Trigger zone on your map (purple box)
2.Set the trigger zone's main script to "plrinzoneactivateused.fpi"
3.In the ifused box, put the name of your enemies example "enemy"
4.Place your enemies around the map and name them "enemy" or what ever you specified in the ifused box.
5.On the characters menu, set the following...
-spawn at start no
-max at any time 1
-maximum spawn 1
-spawn after delay yes
-number to spawn 1
Now, when you run the game and walk through that trigger zone, those named enemies will be spawned. Hope this helps.