Unfortunately, the only way is to hard code the lockword in the job, as in

RUN progname/lockword.groupname.accountname

What you need to do is protect your job files from prying eyes. The easiest way to do that is to place them in a group with EXECUTE all access, but locked down for everything else. It is important to note that the only thing required to stream a job file is EXECUTE access. READ access is NOT required any longer.