Predicting/simulating magnetospheres of exoplanets? Based on atmospheric parameters, size, or distance from the star, is there any way to simulate or predict the magnetosphere of an exoplanet? Are there programs (similar to climate models for atmospheres) that can simulate magnetospheres?
The magnetosphere is usually not generated by the atmosphere, but by the interior ferromagnetic flows of a planet. I say usually not, because Venus is an exception for the terrestrial planets in our solar system.
But in general rocky planets will exhibit a wide range of interior flow conditions, depending on their individual composition and state of cooling.
Gaseous planets can be a bit easier in that case, if one accepts uncertainties about the properties of metallic hydrogen.  

If you then simply go an assume you know all those complicated properties, then sure, you can simulate something. But it's not a scientifically testable prediction only playing around with parameters, as long as it's not tied to a specific object.