I work for the company, DataXstream, who offers a connector (you reference them in the initial message) to do exactly what you want. Typically our connector is used to integrate a 3rd party application into SAP. I'm not sure that you can assume that the iDOC will contain the information you always want, since most SAP implementations are very customized and unique. Anyway, we'd be happy to help you either leverage the connector as is, or the pieces you are looking for to peform the integration you seek. Just let me know.
Jim
