CPYSPLF

I am calling the wm.as400.access:callProgram service from IS 4.6 to run a CL program on an AS400. The CL program that works fine from AS400 command line contains the following commands:
ADDLIBLE LIB(QUSRSYS)
MONMSG MSGID(CPF2103)
WRKSBSJOB SBS(D_MIR$LD) OUTPUT(*PRINT)
CPYSPLF FILE(QPDSPSBJ) TOFILE(P$GBA/GBWRKSBS) +
SPLNBR(*LAST) MBROPT(*REPLACE)

The CPYSPLF command results in an error: Function check. CPF3303 unmonitored by WMJOBLIST at statement 400, instruction X’0018’.
Could someone help me in this one, please.
Thanks.
Gabor