In this work we investigate the vortex dynamics in a square mesoscopic superconducting cylinder in the presence of an applied magnetic field parallel to its axis. The rectangular cross-section of the sample is L² and an engineered columnar defect of area d² at the center is taken into account; L = 12ξ(0) for all simulations while d varies discretely from 1ξ(0) to 10ξ(0). We study the magnetization and the vortex configuration, increasing the magnetic field from zero to the normal state field. We found that for d > 7ξ(0) no vortices in the superconductor area are possible. Also, if the size of the defect is reduced, the nucleation fields decrease.