Hi Andrey,
Sadly that's not the answer I was hoping for 
I have a similar script except this poses 2 issues. I will then need to go an reattach every VM to the "new" network, then set the IP's for each VM's....This script will take a while considering we have 26 civms in 1 civapp. This is a mission especially since I need to do it for every CIvApp I add to cloud.
Any ideas how the GUI does it so simply without destroying the entire vApp network? Is it not possible to achieve the same result even with the restful api or c# sdk?
Thanks!