Check this out:
Text_align.gdg (13 KB)
Anyway, you just have to add this action in the event you “refresh” the text to show a new letter:
Do = "Position_to_be_centered" - Text_Object.Width()/2 to the X position of the Text object“Position_to_be_centered” is the X position where you want the text to be centered (e.g. the centre of the scene)