Help understanding job credentials and permissions

 I want to define up a job in the library that uses privileged credentials... e.g. A job that runs on linux and logs on as Oracle. 

I then want to allow a more restricted account the ability to run this job, e.g. allow a help-desk person to submit the job "on demand" but not have any access to the credentials it runs with.   

 I can't seem to do this, as the credentials set by the owner of the job do not carry over when someone else submits it.

To describe this differently, I would like it to work like a stored procedure where I can create a procedure that uses my privileges, and then grant execute on the procedure to someone else who does not have the privileges to do everything the procedure does.