This paper discusses our approach to the problem of refining high-level simulation specifications. Our domain is simulated combat training for tank platoon members. Our input is a high-level specification for a training scenario and our output is an executable specification for the behavior of a network-based combat simulator. Our approach combines a detailed model of the tank-training domain with non-linear planning and constraint satisfaction techniques. Our initial implementation is successful in large part because of our use of domain-knowledge to limit the branching factor of the planner and the constraint satisfaction engine.