We demonstrate the suitability of the Ag/Pt(111) strain-relief pattern as efficient template for controlling the formation of well defined heteromolecular nanostructures. Two different species of molecular building blocks with complementary end-group functionalities are combined on this surface, which results in the formation of robust bimolecular nanoribbons driven by the interplay of the site specific adsorption on the strain-relief pattern with the highly directional intermolecular hydrogen-bonding intrinsic to the free bimolecular system.