The motion of a Wave Energy Converter (WEC) can be described in terms of a particular integro-differential equation, which involves a convolution product accounting for the radiation forces. This convolution term has a computational and a representational drawback both for simulation, and for analysis/design of control strategies. This study presents an application case of a method to obtain a parametric model of the force-to-motion dynamics and/or the radiation force convolution term, based on recent advances in moment-matching. This allows the computation of a model that exactly matches the frequency response of the original system at a chosen set of frequencies, while enforcing specific physical properties of the device.