Oracle dbms_scheduler for remote agent mangling parameter with double-quotes

Question

I have a dbms_scheduler job running across to a remote scheduler agent to run a powershell script. The problem is that one of the values I am passing is a double-quoted path, and Oracle is mangling it when it tries to put it on the command line:

My job call:

BEGIN
  -- Windows executable job type
  DBMS_SCHEDULER.create_job(
    job_name             => 'test_dstage_job',
    job_type             => 'EXECUTABLE',
    number_of_arguments  => 6,
    job_action           => 'C:\windows\system32\cmd.exe',
    auto_drop            => TRUE,
    enabled              => FALSE);
-- this is a required first parameter to the cmd.exe call
  DBMS_SCHEDULER.set_job_argument_value('test_dstage_job',1,'/c');
-- second parameter is the batch file to run
  DBMS_SCHEDULER.set_job_argument_value('test_dstage_job',2,'Powershell');
-- a bogus third parameter value to be passed to the batch file that we want to see echoed in the log
  DBMS_SCHEDULER.set_job_argument_value('test_dstage_job',3,'-file'); 
  DBMS_SCHEDULER.set_job_argument_value('test_dstage_job',4,'"D:\IIS Project Files\JOBMGMTSYS_DEV\run_dsjob.ps1"');
  DBMS_SCHEDULER.set_job_argument_value('test_dstage_job',5,'-input_values');
  DBMS_SCHEDULER.set_job_argument_value('test_dstage_job',6,'dsProject=RDM;dsEnvironment=DEV;dsJob=s_Main_RDM_WF;wrkflwRunSid=10;pmCD_TBL_LST=ADR_USG,AGE_VRFCTN_DOC_TYP,BUY_SELL_AGRMT_TYP,CLNT_IMPTNC;pmAPLTN_RGSTRY_CD=RDM;RDM_PARAMETERS_SysEnv=PARM_FILE_SYS');
---- set the credential to use
  DBMS_SCHEDULER.set_attribute('test_dstage_job', 'credential_name', 'PREPROD_CREDENTIAL');
-- and the destination
-- can also set destination by the DESTINATION_NAME, or the IP:PORT combo. I’ve tried all three flavours, 
  DBMS_SCHEDULER.set_attribute('test_dstage_job', 'destination', 'ppr235qapp47.pre-prod.prv:8090');
-- and now launch it.
  DBMS_SCHEDULER.enable('test_dstage_job');
END;

But according to the log on the Windows box, parameter 4, the file argument, gets passed to the command line as

C:\windows\system32\cmd.exe /c Powershell -file  "\"D:\IIS Project Files\JOBMGMTSYS_DEV\run_dsjob.ps1\"" -input_values dsProject=RDM;dsEnvironment=DEV;dsJob=s_Main_RDM_WF;wrkflwRunSid=10;pmCD_TBL_LST=ADR_USG,AGE_VRFCTN_DOC_TYP,BUY_SELL_AGRMT_TYP,CLNT_IMPTNC;pmAPLTN_RGSTRY_CD=RDM

So it is changing:

"D:\IIS Project Files\JOBMGMTSYS_DEV\run_dsjob.ps1"

To

"\"D:\IIS Project Files\JOBMGMTSYS_DEV\run_dsjob.ps1""

Adding an extra double-quote backslash to the front, and an extra double-quote to the end.

Any ideas?