We report a study of the modes D_CP K+- and D^*_CP K+- where D^(*) decays to
CP eigenstates. The data sample used contains 275 x 10^6 BB events at the
Upsilon(4S) resonance collected by the Belle detector at the KEKB
energy-asymmetric e^+ e^- collider. The CP asymmetries obtained for D_CP K are:
A_1 = 0.06 +- 0.14 (stat) +- 0.05 (sys), A_2 = -0.12 +- 0.14 (stat) +- 0.05
(sys) and for D^*_CP K : A_1^* = -0.20 +- 0.22 (stat) +- 0.04 (sys), A_2^* =
0.13 +- 0.30 (stat) +- 0.08 (sys).Comment: 10 pages, 7 figures, submitted to Phys.Rev.D (Rapid Communications