Pre-baked shadow maps

(Not LIGHT MAPS) Basically what i'd like to do is to have all lights pre-render the static geometry to its shadow map. Then, provided the lights are also static, it'd be sufficient to render shadow casters of only few dynamic objects in the scene, merging the result with pre-rendered shadow maps of static geometry. I doubt there's built-in support, but is threre a way how to control the light's shadow map rendering?