Cool. We also have the full code of the program on the computer. It is well commented, and it is possible to easily modify it. See
https://github.com/janten/dpt-rp1-py
If I understand things right, when the RP1 first connects to the computer with USB it presents a serial connection, and after some back and forth, it then switches to a USB network connection. If we can understand this first serial communication, it might be good.