We propose an analytical interatomic potential for modeling platinum, carbon, and the platinum-carbon interaction using a single functional form. The ansatz chosen for this potential makes use of the fact that chemical bonding in both covalent systems and d-transition metals can be described in terms of the Pauling bond order. By adopting Brenner's original bond-order potential for carbon [Phys. Rev. B 42, 9458 (1990)] we devise an analytical expression that has an equivalent form for describing the C-C/Pt-Pt/Pt-C interactions. It resembles, in the case of the pure metal interaction, an embedded-atom scheme, but includes angularity. The potential consequently provides an excellent description of the properties of Pt including the elastic anisotropy ratio. The parameters for both the Pt-Pt interaction and the Pt-C interaction are systematically adjusted using a combination of experimental and theoretical data, the latter being generated by total-energy calculations based on density-functional theory. This approach offers good chemical accuracy in describing all types of interactions, and has a wide applicability for modeling metal-semiconductor systems.