The feasibility study of direct open charm measurements by its decay into two daughter particles, pion and kaon, in central Pb-Pb collision at SPS energies of 158 AGeV and 40 AGeV, shows that such measurements are viable at NA61/SHINE experiment if it is supplemented with a dedicated Vertex Detector (VD). We use AMPT (A Multi-Phase Transport model) event generator to generate the physical input for simulation and employed GEANT4 application to describe particle transport through the experimental setup. The VD will allow for precise track reconstruction at the target proximity. The direct open charm measurements will be a challenging due to the low production yield and short life time of D^{0} mesons. The obtained results are based on the predicted yields of D^{0} meson by Hadron String Dynamic (HSD) model. This study also addresses the issue of VD optimization and the emphasis is put on the prospect of the development of a VD based on CMOS technology.