To accurately model the specific detection characteristics of spectral sensors based on linear variable filters (LVFs) within an optical design tool, it is essential to consider crucial position-variable spectral properties, such as peak transmittance, central wavelength, half width, or slope steepness. In this context, we propose a straightforward approach, integrating a dynamic link library (DLL) containing all position-dependent spectral properties of the LVF into a commercial optical design software. Exemplary investigations are conducted for an LVF with a detection range of 450–850 nm. For ease of use, the measured position-, wavelength-, and angle-dependent transmission properties of the LVF have been described through a simple yet highly accurate model system. Moreover, to highlight the essential value of this simulation for specific applications, an efficiency-enhancing spectral module is simulated, which is an LVF-mirror arrangement characterized by a multiple-reflected beam path. The introduced optical design tool demonstrates its particular strength by enabling the optimization of the highest detection efficiency for either the short- or long-wavelength range.