Mod\modname1\events folder
From EU3 Wiki
The events folder contains all the events for a mod. There should not be any subfolders in this folder as of patch 1.1. Any event file that has the same name as a file in the EU3\events folder and is in this mod\modname1\events folder will be used instead of the event file that is in EU3\events (the original files will not be changed even if they are named the same). The code that is used in the mod\modname1.mod file determines how the event files in this directory are used. please see the description of that file to learn what codes can be used and how they work. As an example, we will use event files with the same name as some in the original game and some new ones. Mods can use any name here. Only .txt files are looked for here by the game. For the purposes of ease of editing and ease of troubleshooting, mods should have arranged event files by catagory or by what the events do. Modders can add thier own code into a file such as randomevent.txt but if the modder is only adding code and not changing original code, it would be better to make a new file. As an example, modname1events.txt is a newly created file where as randomevents.txt is a original event file that this example mod is going to change. How to edit or create events
