The CRESST experiment searches for dark matter particles via elastic scattering off target nuclei in cryogenic CaWO4 crystals. A two-channel readout system is applied, measuring the light and phonon signal of each interaction. The ratio between these signals defines the Light Yield (LY) and Quenching Factor (QF). These quantities are employed to distinguish between different incident particles and are hence essential for background discrimination. Within this thesis, experimentally observed LYs and QFs shall be reproduced by developing a simulation model based on Birks Law. This model could simplify and improve the parametrization of the nuclear recoil data. In the ideal case, the phenomenological parametrization employing 9 particle-dependent parameters could be replaced by the Birks parametrization, which only makes use of 2 particle-independent parameters. Our simulations are run within a framework based on Geant4. Problems occurring with processes at low energies are being analyzed and solved. Various energy loss models are compared and a profound insight into the simulation procedure is gained. The final results yield a good estimate of all LY and QF curves. However, they fail in precisely reproducing experimental data especially at low energies (< 100 keV), where Birks Law is not sufficiently accurate.