You were right about the command Ramiro, but allow me to clearify.
The command is, as he said N\[
n]
what you forgot to mention, is that where
n is, you enter the hero's ID NUMBER that you want to be said.
Each hero has a number, you can see them by looking at the database...the first hero of your party is 001, second is 002 and so on.
So if my hero 001's name was...say...Jlanky, this is what you'd do:
It'd go like this: "...hey there N\[001]...whats up?" in your event window
And look like this in the game: "...hey there Jlanky...whats up?"
Too easy.