  We describe the status of the calculation of the branching ratio for the
decay \bar B^0 --> D^+ pi^- to NNLO in QCD factorization. Here, we present the
result for the colour-singlet hard-scattering kernel. The calculation has been
performed using multi-loop techniques like Laporta's reduction to master
integrals, and Mellin-Barnes representations and differential equations for
evaluating the latter.
