How to make a mod that alters in-game events?

I asked this same question on the Steam Community, and they directed me here. You can read what I said originally with that link, but I’ll sum it up here:

I’m trying to make a mod that can alter events in-game. I tried using UME (which I know is deprecated and I shouldn’t be using) but that only allows you to make new consoles/topics/researches, you can’t edit items in the game already. This might sound cliché, but, the Dreamvast. I have a mod that will change marketshare of a console if you make a good game for it. It works like a charm on the Dreamvast, but when that blasted PS2 comes in, the dialog boxes saying “sorry we’re cancelling the Dreamvast” still appear and the console still gets discontinued early, as usual. What I’m looking for is a way to alter the game’s story so that those dialog boxes don’t appear and the Dreamvast gets discontinued later. How might I be able to do this? I’m… unfortunately not very good at coding.