distiction between reflective and refractive caustics per ob

[flipside]

distiction between reflective and refractive caustics per object:
like this:

recieve caustics:
-reflective: ON/OFF
-refractive: ON/OFF

generate caustics:
-reflective: ON/OFF
-refractive: ON/OFF

For example a glass object, I want the nice caustic pattern generated by refracted light behind the object, but not the dull reflection caustics in front of the object.

thanks,

flipside