Script for rotating multiple IP address every 30 minutes windows server 2008R2

We have one newsletter server which sends reports and ezines to the opt-in database of 4,75,000 users four times in a day. Our application is managing the mail merge and through put very well but the challenge is on mail delivery cluster. We have a cluster of 6 mail servers catering to this huge load. There is one master distribution server which we use to distribute the traffic to the 6 servers on round robin fashion therefore the load is balanced. The challenge is that these 6 mail servers if operating on one single IP address get into bulk precedence and so for that we have added 10 IP's to each windows server.

I need to rotate these static IP's on the server on hourly basis using either some script or software for which I seek experts help. it should rotate the IP's from 1-10 each on hourly basis.

Thank you in advance for kind assistance :)

Tips:

Please check this link:

http://social.technet.microsoft.com/Forums/en-US/winserverpowershell/thread/aef47e01-f849-45f3-ad8b-ebff855ddd08

But this answer not clear so i can't get so please explain me :

what is this :

You can assign a static IP using the following WMI call. What do you have so far for looping through the IP's and for time detection? Of course you'll need to set the values for $nic_ip, $nic_subnet and $nic_gateway.

$NIC =Get-WmiObject-ClassWin32_NetworkAdapterConfiguration-Filter"IPEnabled=TRUE"#assign static IP address
$nic.EnableStatic($nic_ip, $nic_subnet)
$nic.SetGateways($nic_gateway)

N.SATHISHKUMAR, MICROSOFT STUDENT PARTNER, INDIA.