The problem is that there is no "internal software." As you correctly assume, all cameras capture in a RAW mode, but the "firmware" code determines which type files these data get saved to and which formats, compression levels, etc., are used.
Even if you had the ability to hack the firmware, there may not be sufficient capacity in the chip used to hold additional code to output the RAW data itself. Then once you overcome that obstacle, you still have no RAW converter. You would have to write your own since no major provider of RAW conversion software is going to take the time to develop a RAW conversion program for a camera which only you and perhaps a handfull of others have an interest in using in the RAW mode.
I suppose it's not out of the realm of possibility, but certainly not really worth the effort unless you have a compelling need for RAW on the CP4500. The jpg algorithms for the CP4500 are quite good with low compression, and tiff is available, so RAW would have been nice, but at the time the CP4500 was released few consumer grade cameras offered this.
Best regards,