After searching a little bit, I found this patent reference from 2002 for a "Declarative data transformation engine": http://www.google.com/patents/US20070220022 (Disclaimer: that kind of patents are the reason why I think the american software patent system is totally flawed and needs to be changed). However, I don't know if someone made a product out of this for the usage you described above. In theory, that should be possible.