A Monte Carlo simulation is performed on a lattice model of a binary mixture of nematogenic liquids and polymers to study the main aspects of phase separation including the influence of external surfaces. The system was investigated at various temperatures, concentrations, and degrees of polymerization. The results seem to fit well within Flory-Huggins theory predictions. It is also shown that in some cases the anisotropy plays an important role in structure formation. The influence of the external surfaces on the condensation of one of the phases was studied on systems that experience the separation by nucleation and growth. It has been noticed that the surfaces that prefer nematogenic molecules act as better condensation nuclei, especially if they are ordered.