Unfortunately, according to my knowledge, no. There is no tool that converts G9 RAWs to DNG. ArtDen stopped developing this tool and it looks like there is no interest on updating it since the G9 produces its own Canon CR2 files.
What I would do in your shoes is download the DNG4PS source and try to include G9 RAW support myself. It might be easy it might be difficult but that is the way things get done in this comunity. "Feature requests" don't get much answers but if you try to do it yourself and get stuck, I bet you'll get the more experienced member's atention.
On the other hand, if you respond that you have absolutely no idea what "source code" is, then I recomend you find another way to achieve the JPG hot-pixel correction thing you are looking for. I bet you are not the first person to try to solve it and the solution must be out there, even if it is not CHDK.