Sorry,
I probably don't understand what you try to achieve.
To my understanding ZPM is targeted to IRIS and its applications and
NOT to the underlying operating system.
- Though I admit that a lot of "hacking" into the OS is possible from IRIS. 

With the broad range of operating systems supported by IRIS, 
I rate this as a rather questionable approach, that I wouldn't support. 
 

just tried to reproduce a similar case in Terminal.
#0) clear all stored  breakpoints (menu: Debug / View breakpoints / remove all)
#1) set the breakpoint in Studio using F9
#2) attach to process (shell if in Terminal)
#3) do ^yourroutine in terminal
#4) In Studio: <ctrl>+<F5>  let it run 
if your breakpoint is reached you see the yellow box

Hint: try it with some simple 5 line routine first

If you never see the yellow box then you just don't execute this line