The present paper addresses the use of a Windows™ DLL to simulate the real code of a DSP for faster development time and advanced testing, especially in high power systems. The development of power system control usually starts with simulations and the development of the control is done with the simulation tool native blocs. Once the control is validated in simulation it is usually C coded into a DSP and real test can be performed. The present paper introduces a way of simulating the real DSP code to fill the gap between simulation and reality. By generating a DLL, the DSP C Code can be called by the simulation tool (in our case SIMSEN). The power part is 'analogically' simulated with a small integration step, and the DLL is called 'digitally' at a given sampling time. A 3-level VSI SVC is used as a guideline to illustrate the concepts presented.