[Script] Help on Pokemon Emerald Intro

I am fairly new to this, but can anybody give me some advice on how to change the titlescreen, cutscene, and the script that Professor Birch gives at the start of the game?

I found the solution for Pokémon Emerald:

You have to go to address 0x2c897b in Hex Maniac Advance and then you can edit the text. My question is, how can you repoint this text so that it reads off of a larger text string in free space?