cp/login/authenticate into Control Panel after CAS authentication in EE 2.8.1

Hi,

How can I cp/login/authenticate into Control Panel after CAS authentication?

if (phpCAS::isAuthenticated()) {

{do EE authenticate}

}

i.e., how can one programmatically login to the control panel that achieves the same results as…

<form action=”/admin.php?/cp/login/authenticate” method=”post”> <input type=”hidden” name=”return_path” value=”” />

Thanks Sara