As far as I can tell, in the XP engine, you can set a default event graphic to be a tile from the current tileset, but through the "change graphic" option given when setting a movement route you can't.
The specific problem I'm having is that I am trying to animate a treasure chest opening. The tileset has all of the frames needed, however I can only use two, one as a tile in the map, and one as the default event graphic. The animation has a total of four frames. Is there any way to do this just using the default engine? Oh, and to specify, I tried importing just the chest animation into the charset graphics, and that didn't work.