You're going to want to stick it in the "Config.cfg" file. It's right in your Star Trek Legacy folder, so you don't need to go digging through anything else. And yes, you can use Word, but when opening you'll need to get it to search for "all files", otherwise it won't pick up the .cfg file. Still, a simpler text editor such as Notepad would be better. But don't stick the // before it. In coding, that denotes a "comment," which is used by developers to help understand what they're writing. When the program is reading the code, it will ignore anything with a // before it, so it's also used to remove erroneous code until it can be fixed. So don't put it there.
Hope that helps.