In Windows 7, how to create a route for a dial up PPTP VPN in powershell

#
# VPN Route Fixer 

$VPNName     = "VPN Name"
$NetToRoute  = "172.x.x.0/x"

#-----------------------------------------------------------

# Dial the VPN Connection 
rasdial $VPNName

# Get the IP Address of the VPN Connection 
$vpnObj = Get-WmiObject -Namespace 'root/standardcimv2' 
       MSFT_NetIPaddress  | 
       Where-Object { $_.InterfaceAlias -eq $VPNName } | 
       Select IPAddress
$vpnIP = $vpnObj.IPAddress  



route add $NetToRoute mask 255.255.255.0 $vpnIP