Workobject offset by moving MD7

Hello I am a beginner in RS. I am doing a simulation in RS where an IRB 5500 is mounted on top of a Cart, which runs along a workpiece. Since the workpiece is not placed the same every time, a sensor must touch the workpiece, and log the position. The Workobject must then move so that the entire program is moved. Does anyone know how to do this, what the program code might look like.