Nanofibrous structures are widely used in filtration, membrane separation, protective materials, biomedical systems, and other transport-related applications. Numerical simulation of flow and transport phenomena in such media requires a reliable geometrical representation of the fibrous domain. However, generating controlled fibrous geometries, particularly random and disordered structures with prescribed fiber diameter, orientation, and density, remains a challenging and time-consuming step in computational modeling. In this study, a MATLAB-based computational code coupled with COMSOL Multiphysics through Live-Link is developed to generate micro/nanofibrous structures inside a cylindrical computational domain. The proposed framework enables the construction of a single fiber with arbitrary dimensions, arrays of parallel fibers, fibers with prescribed orientations, and fully random fibrous networks. The code allows independent control over key structural parameters, including fiber diameter, fiber number, fiber density, orientation, spatial distribution, and computational domain size. Moreover, fibrous structures can be generated using uniform or non-uniform fiber diameters, making the method suitable for representing both idealized and more realistic fibrous media. The generated geometries can be directly used in COMSOL Multiphysics as initial computational domains for the simulation of fluid flow, pressure drop, permeability, particle transport, and other coupled physical phenomena. The developed MATLAB–COMSOL Live-Link framework provides a flexible and efficient tool for rapidly constructing parametric fibrous geometries and systematically studying the effect of microstructural parameters on transport behavior in fibrous media. This approach can facilitate the design, optimization, and numerical analysis of micro/nanofibrous materials in filtration and related applications.