Hi Lalewicz,
Have you looked at Matt Faus's HowTo on how to update SharePoint lists using InfoPath? There is also an example in Chapter 9 of our book. I'm not sure either is what you want, but without understanding your requirements in more detail, my first response is to look at them. Send me or Matt e-mail, and we can help you with pointers.
Patrick Halstead
Project Manager at Qdabra