This paper presents a software module, named tracking plug-in, developed to automatically generate the source code of software interfaces for managing the interaction with low cost hand-tracking devices (e.g., Leap Motion and Intel Gesture Camera) and replicate/emulate manual operations usually performed to design custom-fit products, such medical devices and garments. The proposed solution is based on the Eclipse platform, a free integrated development environment (IDE), that allow us to manage the automatic code generation in a simple way after having defined the target application using a meta-model language, in our case the UML class diagram. First, we describe the background as well as the main problem, then, the software solution and adopted tools (i.e., Eclipse and Acceleo). Finally, the preliminary tests carried out for two applicative contexts (prosthetic and textile/clothing) are presented.