Touchscreen Monitor Presentation

Keynote (latest version) on iMac 27" late 2014.

I have created an interactive presentation which will run on a touchscreen monitor. The "home" page (slide) has buttons which link to various slides. I have got this all working perfectly, but if someone touches the screen outside these buttons, the presentation moves to the next consecutive slide as if the mouse button had been clicked.

is there a way that I can have only the button areas and their links live and effectively turn off the mouse button click?

In other words, I want pressing the buttons to be the only way of advancing the slides. The monitor will be on a stand at an event for a charity.

I Hope this makes sense.