  We study the entrainment of a localized pattern by an external signal via its
coupling to zero modes associated with broken symmetries. We show that when
internal symmetries are broken, entrainment is governed by a multi-degree of
freedom locking dynamical system that has a universal structure defined by the
internal symmetry group and its breaking. We derive explicitly the universal
locking dynamics for entrainment of patterns breaking internal phase symmetry,
and calculate the locking domains and the entrainment structure for the example
of complex-Ginzburg-Landau solitons.
