I'm not personally very experienced with Scheme's. This might be something you want to contact a partner about building. It looks like it should be fairly simple but unfortunately I'm not quite certain how to implement this. Maybe if you posted what you have developed so far someone could help out with ironing out what you need to do.
Community Support Team _ Alex Rezac If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.