This study presents a soft computing tool for the computer-aided design of disturbance rejection FOPID controllers based on the maximization of Reference to Disturbance Ratio (RDR) index. The study illustrates the utilization of software routines to implement a soft computing scheme in order to solve a closed loop disturbance rejection FOPID control system design problem for a target gain margin specification. Authors demonstrate that the complex design efforts, which involve a high level of mathematical knowledge, can be easily performed by using basic software routines when soft computing techniques are employed effectively in the computation processes. Illustrative design examples are shown to show effectiveness of the proposed design method.