  Motivated by experimental results on $\bar B\to D^{(*)}K^-K^{0}$, we use a
factorization approach to study these decays. Two mechanisms concerning kaon
pair production arise: current-produced (from vacuum) and transition (from the
$B$ meson). The kaon pair in the $\bar B {}^0\to D^{(*)+}K^-K^0$ decays can be
produced only by the vector current (current-produced), whose matrix element
can be extracted from $e^+e^-\to K\bar K$ processes via isospin relations. The
decay rates obtained this way are in good agreement with experiment. The
$B^-\to D^{(*)0}K^-K^0$ decays involve both current-produced and transition
processes. By using QCD counting rules and the measured $B^-\to D^{(*)0} K^-
K^0$ decay rates, the measured decay spectra can be understood.
