I'm attempting to implement a small game project using a data driven design in which much of the information is read-in from external files for the sake of flexibility. Using this type of design is a bit of a challenge, though, and I've stumbled across a problem.

I have a type of agent in my game that chases other entities in the game world. When it's constructed it needs to know what it's chasing. The things that it is able to change, however, are also being created from external files and may be of several different types. What's a good way to be able to associate these Cheaseable objects with the Chasers?