you could try this, which may make it a little easier, though i have not messed around with it myself. you would simply set different exposures, and save them to a material library. then you would replace the lens shader per view you are rendering. it would still be a two step process.
http://www.germanmentalray.de/viewto...rephotographic
what they need to do is set the exposure up as a modifier that is applied to the camera, much like the lens correction. then you could have per camera exposure.