Hi ,
Have you tried giving variables for the input for -VM and -DeviceName i.e
$vm= get-vm myvm1
$deviceName=($host1 | get-Scsilun | where {$_.CanonicalName -match "naa"})[0].ConsoleDeviceName where the value in the [] depends where your naa id listed when you type the command ($host1 | get-Scsilun | where {$_.CanonicalName -match "naa"})
then type the command
new-harddisk -vm $vm -DiskType RawPhysical -Devicename $deviceName
Hope this information helps you