You can get all the IP addresses with GetHostAddresses like this:
$ips = [System.Net.Dns]::GetHostAddresses("yourhosthere")
You can iterate over them like so:
[System.Net.Dns]::GetHostAddresses("yourhosthere") | foreach {echo $_.IPAddressToString }
A server may have more than one IP, so this will return an array of IPs.