Vehicle Network Toolbox: Can a message be transmitted using 'Transmit' block onto a live CAN channel, but bearing the transmitter ID as one of the already connected ECUs in the network?

To briefly explain what I am looking for: Consider that I have a vehicle system setup in lab which has all the required ECUs connected. I am currently using this setup to verify the software/function. Now say I need to test a function which is already present in one ECU, but I will mask(comment) that function implemented in the ECU, and model the same function in Simulink. Now I want to transmit/receive all the messages related to that function from/to the model instead of ECU. Also while transmitting any message from model, I want all those to be treated by other ECUs as though the original ECU where function was implemented is transmitting it. This will require 2 nodes (one ECU and Simulink model) to have the same address ? Is this allowed ? Or is there a better way to achieve what I am planning to do.

Please let me know if I have issues with some basics here(CAN, VN toolbox understanding etc.). Thank you very much :)