Live update of presentation?

I'm in a situation where I want to present a diagram to a group of people on a second screen, and I want to update the data of the diagram without "breaking" the presentation. It's for a live TV-broadcast, and I'm keeping track of different data during the show that I need to push to the production team. Does anyone know if this is doable in Keynote, or if there is any other solution for Mac or some web-based solution?

thanks!