In this work we study a generalized Nevanlinna Pick interpolation problem, where transmission zero locations are imposed. Unlike in other variant of this problem considered by T.T. Giorgiou et al. the interpolation points are chosen on the boundary of the analyticity domain: that is, in our framework, on the real axis. This problem is motivated by important questions in electronic and microwave system design, and it relates to the broadband matching theories of Youla and Helton. An existence and uniqueness theorem is proved. The constructive proof is based on continuation techniques.