Hi Sam, you'd need a way to get the text mesh hollowed out (maybe using a shell modifier) and cut off the top so that the liquid can enter there. Then it's a matter of placing the emmiter, assuming you want to fill it top-down. Or maybe even using the inside faces of the hollowed out text as an emmiter (with PFlow, for example) to fill bottom-up.
Marsel Khadiyev (Software Developer, EPHERE Inc.)