How can we grant execute on specific job to another user?

   I have two users A,B  . User A has create jobs privs+others .

  user B have connect,resource.   User A have job named Test .

This job using external (Batch file under OS)

    I need to know how can I give grant to User B just grant on job test which owned by user A.

 This is for security wise . just need to give Users exeution on jobs and jobs created under user A . user A locked.

Any idea about that.

 Thanks in advance
Mohammed