This document is organized as follows. The first Chapter illustrates the physical motivations of the MesonEx program, and presents the experiment. The second Chapter describes the CLAS spectrometer, its upgrade to CLAS12, and the new Forward Tagger Facility. Chapter 3 shows the detailed characterization of the FT-Cal components, and the results obtained from the two small-scale prototypes. Chapters 4 and 5 contain, respectively, the description of the amplitude used to generate pseudo-events for the reaction γ * p → pπ 0 η, and the analysis of the CLAS data used to validate the model and fix the free parameters. Finally, the sixth Chapter describes the full partial wave analysis performed on the MesonEx pseudo-data, used to estimate the sensitivity of the experiment to the discovery of a possible exotic meson.