Windows Server 2012 R2 and Windows 8.1 contain a nice function for import-PFXCertificate. However if you mange an older operating system you can use a different function:

function Import-PfxCertificate {
 
param([String]$certPath,[String]$certRootStore = “CurrentUser”,[String]$certStore = “My”,$pfxPass = $null)
$pfx = new-object System.Security.Cryptography.X509Certificates.X509Certificate2
 
if ($pfxPass -eq $null) {$pfxPass = read-host “Enter the pfx password” -assecurestring}
 
$pfx.import($certPath,$pfxPass,“Exportable,PersistKeySet”)

$store = new-object System.Security.Cryptography.X509Certificates.X509Store($certStore,$certRootStore)
$store.open(“MaxAllowed”)
$store.add($pfx)
$store.close()
}
Export-ModuleMember -Function 'Import-PfxCertificate'