Virtual humans (VHs) are used in many educational and entertainment settings: training and serious gaming, interactive information kiosks, tour guides, tutoring, interactive virtual dancers, and much more. Building a complete VH from scratch is a daunting task, and it makes sense to rely on existing platforms. However, when one builds a novel interactive VH application, one needs to be able to adapt and extend the means to control the VH offered by the platform, without reprogramming parts of the platform. This paper describes Elckerlyc, a novel platform for controlling a VH. The focus is on how to easily extend and adapt the system to the needs of a particular application, without programming.