In analogy with the study of copulas whose diagonal sections have
been fixed, we study the set Ch of copulas for which a horizontal section h has been given. We first show that this set is not empty, by explicitly writing one such copula, which we call \textit{horizontal copula}. Then we find the copulas that
bound both below and above the set Ch. Finally we determine the expressions for Kendall's tau and Spearman's rho for the horizontal and the bounding copulas