Yes, please see https://www.youtube.com/watch?v=UAZuflGNEps&index=7&list=PLS8vhyBd_bXnly7paSPdvwt2r7xKMo6tV


A detailed write up in available in the user manual under the section "How to write custom code in NetSim"


Also refer:

What components of Visual Studio Community 2019 to install and configure to work with NetSim source codes?

What components of Visual Studio Community 2017 to install and configure to work with NetSim source codes?

Which version of Visual Studio is required for NetSim?

I have modified the source codes and built successfully. But it has no impact on simulations performed. Why? 

Why does an error pop up arises when opening the NetSim.sln file through visual studio. ?

What are some best practices for writing my own code in NetSim?