We study the interaction between an exciton condensate and nuclei in GaAs/AlGaAs coupled quantum wells using an oscillating (RF) magnetic field. We demonstrate that electron-nuclear spin exchange can polarize the nuclei within the quantum well where the electrons are located over a macroscopic area of ~105 𝜇𝑚2, and at a critical static magnetic field of B = 1.750 T, complete nuclear polarization in the quantum well is achieved. We find that the electron-nuclear hyperfine interaction, 𝑔, is enhanced by a factor of √𝑁, where 𝑁 is the number of excitons in the condensate. This enhancement gives rise to a collective RF mode of the condensate at √𝑁𝑔, which could serve as a sensitive probe for condensate coherence.