Do you mean just random text or project text? If it is project text (client name etc.) ou can modify one of the support files and this is automatically updated across all the drawings.
If you mean just random text that (may) appears in every drawing then a batch process of a LISP routine is probably the best way to go. I assume your batch process is a script in which case you can script whatever you want, it doesn't have to be a plot routine.