We report the study of internal ordering and electro-optical response of dual-frequency nematic liquid crystals (DFNLCs) confined to microporous polyethylene terephthalate (PET) membranes. The DFNLCs are characterized by positive/negative signs of dielectric anisotropy in low/high-frequency electric fields E. Microscopic observations assisted by numerical simulations identified the escaped radial (ER) configurations of the nematic director field within the porous membrane for E = 0. Low/high-frequency electric fields were applied to the PET-DFNLC membrane to manipulate the internal nematic configuration. We found that the low/high-frequency electric fields transform the ER structure to the quasi axial/planar radial, resulting in the suppressed/increased propagation of near-infrared electromagnetic radiation through the composite material. The results are discussed for photonic applications.