Import and bind a cert is IIS.

param (
[Parameter(Mandatory=$true)][String]$certpath,
[Parameter(Mandatory=$true)][String]$certpass,
[Parameter(Mandatory=$true)][String]$ip,
[Parameter(Mandatory=$false)][String]$website = "Default Web Site"
)

$mypwd = ConvertTo-SecureString -String $certpass -Force –AsPlainText
$cert  = Import-PfxCertificate -FilePath $certpath Cert:\LocalMachine\My -Password $mypwd -Exportable
$bind = Get-WebBinding -Protocol https -IPAddress $ip  -port 443
if($bind -ne $null) {
    Remove-WebBinding  -Protocol https -IPAddress $ip  -port 443
}

# -Name $website -IPAddress $ip -Protocol HTTPS -Port 443 -HostHeader '' -Binding $ip':433:'
new-WebBinding -Name $website -IPAddress $ip -Protocol https -Port 443 
$bind = Get-WebBinding -Protocol https -IPAddress $ip  -port 443
$bind.AddSslCertificate($cert.GetCertHashString(), "my")

This is for a cert to IP without host header.