We report on our first experiences in simulating Neuberger valence fermions on CLS $N_f=2$ configurations with light sea quark masses and small lattice spacings. Valence quark masses are considered that allow to explore the matching to (partially que
nched) chiral perturbation theory both in the $epsilon$- and $p$-regimes. The setup is discussed, and first results are presented for spectral observables.
