There's a bug in this right now, so it won't happen automatically, but you can do it manually as a workaround, until it's fixed:
Break the dialogue where you want (it's generally taken to be correct to leave at least two lines of dialogue on each page, and split only at the end of a sentence), by hitting enter twice. Move up a line and retype the character name, and you'll get the "(CON'T)". Move up to the end of the previous dialogue, hit enter, then type a parenthesis. You'll get a parenthetical, in which you should write "MORE".
A fix for the automatic version is in the works...