Please don't ask the same question multiple times. The people here who can help you read all postings and will answer when time permits and they have something to say.
You probaby need to study what CHDK RAW/DNG actually is. There is a lot of good information here :
CHDK Links : Raw & DNGThe short answer to your question is that a RAW/DNG image is a dump from the camera sensor with no corrections applied. What you see is what the camera sees. So you need to correct any lens distortion effects in post processing (i.e. on your PC). You may be able to use a lens profile with your post processing software to make this easier.