-Nosteam is something you would add yourself, and it has nothing to do with editing the .dll files.
For reference, the user is referring to this post.
If you need to check to see if -Nosteam was added, you just right click the game (Conan Exiles), and select Properties. From there, under General is a section for “Launch Options.” If that was your issue, there would be an entry for -Nosteam right there. It’s not really something that gets added on it’s own, a developer (which Funcom didn’t) or the user (you) would have added it.
Perhaps you are making this more complicated then it is? What do you mean by “it’s not working”? Are you running any mods, such as the Offline Mode mod (which states is not compatible with DLC’s)?