Mewtwo Strikes Back
All that really has to be done is to find the Platinum code and copy and paste that code over the HGSS one. However, I have no idea how I would go about doing this.
Sorry, but no. You can't just "copy and paste" from Platinum or something. If the name can have up to 5 letters, it's pretty safe to say the memory area reserved for the player's name can use only up to 5 spaces, and what's next is sure used for other stuff.