Application that monitors a MFP (Lexmark) by NPAP protocols

We need an application that monitors a MFP (Lexmark) by NPAP protocols, on the port 9300, and capture npap packages sent from it. These packages must be captured when performed some copy of a document in a MFP. In this packages must be read how many pages were copied and which user. These information must be written on XML file. Must be written in Java or C #. Pm for more details.