That depends on what kind of Mod you are trying to do. If your mod provides something to the Main campaign of the game then you need to create your mod with a dependency to the Main. (i.e. Have the Main check-box checked when creating your mod). Then those goals will appear in the Editor. But they will have a grey background indicating that they are read-only files.
However, if your mod does not provide content to the Main campaign. Then, finding the files for the story editor will get more complicated. But, of course, there are solutions.
So, important question is that does your mod provide content to the Main campaign ?
