Anything launched by $zf(-1) is going to run as the user that is running the original process. In the case of a Caché terminal session, that will just run as whatever user is running the terminal, and there's no way to get around that.
If you were to use another method to run the $zf command, such as a Telnet connection, or running it via the Caché task manager, the process would instead run as the user who owns the Caché Controller services. So, if you REALLY need to be able to run cmd as an administrator, the best way would be to make the user who owns Caché the system administrator user, and then run this code via the task manager (you could use a RunLegacyTask).
All that said, I have to agree with Rubens, this is not an ideal setup for security reasons, why can't you just make it such that your executable will run without the need for administrator access? Is there a particular reason why it requires administrator rights?