The effect of stretching polymer chains bearing helical segments induced by hydrogen-bonded chiral molecules in the mixtures of chiral molecules is theoretically studied. The end-to-end distance R of a polymer with induced helical sequences and the chiral order parameter psi (difference in the content of left- and right-handed helices on a chain) are calculated as functions of the external tension given at the chain ends. The chiral order parameter is shown to be sensitive to chain extension and drastically enhanced by stretching. With the slightest enantiomer excess, therefore, a mixture of chiral molecules in a solution can be separated into assemblies of pure chirality by repeating the operation of stretching polymers and washing the adsorbed chiral molecules. The possibility of optical resolution of racemic solutions by stretching polymeric gels consisting of such hydrogen-bonded helical subchains is discussed.