For the model-based active control of three-dimensional flows at high Reynolds numbers in real time, low-dimensional models of the flow dynamics and efficient actuator and sensor concepts are required. Numerous successful approaches to derive such models have been proposed in the literature. We propose a software environment for a comfortable and performant testing of control, actuator and sensor concepts which may be based on such models. It is realized by providing an easily manageable MATLAB control interface for the k-``- model from the FEATFLOW CFD package. Potentials and limitations of this tool are discussed by considering exemplarily the control of the recirculation bubble behind a backward facing step.