VPN whit surface RT using a Group Name And Password (Secret)

We are looking to make a conection with  Surface rt to ASA with IPSEC through Cisco.

Whir IOS and client Cisco give us the option of Group Name and Password for the shared secret.

Windows RT Surface have not seeing this option for  Group Name and Password

Is there some kind of combination of username password that would go in the "Use preshared key for authentication" field (such as "username;password" or some other format)?

We and other LARGE corporations will require this feature to implement  VPN un Surface RT, please give us a workaround or fix it ASAP.