USB Peripheral CDC-EEM (Ethernet Emulation Mode) driver

I would like to implement the support of USB CDC-EEM (Peripheral) with the USB basic firmware V1.30 (on a RX72N). Does anybody have any experience with it (especially with the CDC-EEM implementation) ? I have all the documents from the usb.org regarding CDC and EEM. For the TCP/IP support lwIP is used. The lwIP stack is running (verified with simple SLIP implementation over a serial interface). The USB Peripheral part is also running with CDC an a simple echo application.
Any support would be welcome.