Custom DXR shader integration

Greetings, I was not sure if this post should be here or in the Rendering category but here goes:
One of my goals is to create a set of my own DXR shaders (ray-gen, miss, closest-hit, etc.) in order to implement a raytraced underwater caustics system. The problem is that I am not sure if at first something like this is currently possible and secondly how this can be done. I haven’t found any relevant resources on the Internet for custom DXR shader integration to the engine, therefore any links, guides or help on the topic would be much appreciated.

I am also very interested in a guide to do something similar. I would like to implement a raytraced subsurface scattering shader.