To understand the interplay of magnetism and superconductivity in oxypnictides, we have studied simultaneous carrier doping in different layers of CeOFeAs; F in CeO and Co in FeAs. The rf penetration depth shows exponential temperature dependence with gap values ∼1.9 and 1.6 meV for optimal F-doped and F & Co-doped samples respectively. The thermoelectric power data for CeOFFeCoAs can be divided into multiple regions and every region could be fitted with appropriate temperature dependence. The dominance of different scattering mechanism is discussed with respect to F and Co substitutions. © 2011 American Institute of Physics.