Display text (Closed caption like) from a file with a shortcut key

Many thanks for this very useful application for creating screencasts.
Could it be possible to somehow to tweak this app so as to display one line of text at a time from a text file.
So in a screencast session instead of using audio narration, the step that is being illustrated can be displayed as text. (Very much like closed caption). Then all the steps for the screen cast can be made into a text file where each step is separated by a delimiter like new line. At the click of a hotkey, the app displays one line of text at a time onscreen.
This is a great feature for those of us with different accents than the mainstream users to convey the narration onscreen.