if you look at the events.txt, you'll see this :
Code:
Trigger X Type:
  Item Given To Monster
  Monster Killed
  Monster Talked To About Topic
  Quest Completed
  //Character At Location
  //Action At Location
  //Item And Action At Location
  //Monster at Location
  //Spell Cast At Location
  //Terrain Destroyed At Location
  //Map Load
  //Quest Completed
Result X Type:
  Quest Completed
  Quest Failed
  Quest Visible True
  Quest Visible False
  Display Text
  End Game
  Play Music
  //Transport Character
  //Change Terrain
  //Move Item
  //Move Monster
  //Enable/Disable Event
  //Record Time
  //Change Talk
  //Display Special Effect
the ones with a // are those that were meant to be added, but currently won't work, sadly, the two things you want to do (character at location and change terrain (I think)) are currently not working 
edit : looking at this again, the trigger seems to have two 'Quest Completed' events, one that works, and one that doesn't work?