Can I convert jpegs to RAW?

I did not notice that the camera settings were changed during a professional sensor cleaning. I shot in large jpeg mode. Can I convert the jpegs to RAW? I know that all cameras actually shoot in RAW and throw away info when on jpeg setting. Can the CF card Sandisk’s Extreme III do this conversion for me?

it may be possible, although i do not know a program that would, but the quality would most likely be pretty bad.