Also, for the specific case of OS/360 JCL (if I recall correctly) was the IBM in-house scripting language which was cobbled together so the machines that were being developed would be usable while the software people wrote the real scripting language that would be shipped with production machines. The "real" one wasn't ready in time, and so JCL became the standard, warts and all.
By all means, implement a job control language in COBOL; either through emulating, porting or interfacing. Even if comes to nothing, you will learn much about both COBOL and scripting languages.
-- Charles