OpenRAW

I currently use Canon EOS digital rebel to take my pictures. What I found annoying is, that when I'm working with the RAW images on my computer and use Canon software, I'm unable to save modified settings back to the RAW file as a set of settings similar to "As Shot". This missing functionality forces me to redo the same setting adjustements over and over again, when I'm working with the same file some time later. I'm an occasional programmer and I was thinking about writing my own software to do so, but without fully knowing the file format it is difficult to do.