  The decays $\bar{B^0} \to D_{sJ}^+ K^-$ and $\bar{B^0} \to D_{sJ}^- \pi^+$
are studied for the first time. A significant signal is observed in the
$\bar{B^0} \to D_{sJ}^*(2317)^+ K^-$ decay channel with ${\cal B}(\bar{B^0} \to
D_{sJ}^*(2317)^+ K^-) \times {\cal B} (D_{sJ}^*(2317)^+ \to D_s^+ \pi^0) =
(5.3^{+1.5}_{-1.3} \pm 0.7 \pm 1.4) \times 10^{-5}$. No signals are observed in
the $\bar{B^0} \to D_{sJ}^*(2317)^- \pi^+$, $\bar{B^0} \to D_{sJ}(2460)^+ K^-$
and $\bar{B^0} \to D_{sJ}(2460)^- \pi^+$ decay modes, and upper limits are
obtained. The analysis is based on a dataset of 140 fb$^{-1}$ collected by the
Belle experiment at the asymmetric $e^+ e^-$ collider KEKB.
