that guy is me, what is needed it the vmware.hv.helper module from the powercli example scripts at GitHub - vmware/PowerCLI-Example-Scripts

What you can now do is this:

Set-HVMachine -HvServer $vcs -MachineName machine.fqdn -User "domain\user"

or

Get-HVMachine -MachineName machine.fqdn | Set-HVMachine -User user@domain

thanx to another contributor of the module