Dynamically change text in Keynote slide using Applescript

Question

What i am wondering is, is there a way to load up a keynote slide, have the slide run an applescript(which reads a text file) and takes that information and uses it to populate text fields on that keynote slide?

Example: Open Keynote presentation. Play the presentation. When we get to slide #4, launch the applescript to get the info that you need from the text file, then populate the text field.