hi, you can follow the procedure in the help document FAQ -> how to add user-defined devices?
by the way, the cx600 has been removed from the ensp in version 510, if you want to use the CXxx simulation you can install version 390 which contains the CX200 and NE5000E, but I didn't find the ATN9xx, for more details you can refer to the FAQ.
hope this could help you,