YuMi Execute program with web services

Machinemike

Hi! 
I participating my schools robot academy program and got myself into a making a task that seems impossible to me.

So. My groups task is to sometimes demo YuMi at exhibitions and fares. Students before me got an old ipad tablet which could be used to start and stop a demo.
I figured out that it could be done with the robot web services.

I got the example "hellorobot" working nicely and i can roam around the robot with URL addresses. But i cant understand how to execute a program using it.
So i have a template for few buttons in html but i need some help with how to direct what folder and what command i can use to start a program.