run powershell commands using system.callSystem()

Has anyone been able to invoke powershell commands using system.callSystem()?

Here's what I've tried

var response = system.callSystem("powershell.exe /command \"& { gci }\"");
alert(response);

if I try the command from cmd or the windows-r run command thingy I get a directory listing—as expected, but from extendscript I get nothing. I've tried all sorts of variations. Or is cmd the only shell that can be run from system.callSystem()?