I've made a back office where people log thereself on 'global' login page and then have acces to various modules including Roundcube. Maybe this can help you.
I've changed a couple of things in rc.
Once the user is logged in here is the link to RC:
<script>ouvrir_lien('../lobomail/?_action=login&_task=mail&login=<? echo $tab_user['user_mail'] ?>&pass=<? echo $tab_user['user_mail_mdp'] ?>&host=<? echo $tab_user['user_mail_imap'] ?>')</script>
The JS function simply open the link in an iframe no need to give it to you.
Then in the index.php of RC i've got this:
// try to log in
if (($_action=='login' && $_task=='mail') || ($_action=='comp' && isset($_GET['cust_id'])))
{
if(isset($_GET['host']) && isset($_GET['login']) && isset($_GET['pass']))
{
    $host=$_GET['host'];
    rcmail_login($_GET['login'],$_GET['pass'],$host);
    if($_action=='comp')
    {
        header("Location: $COMM_PATH&_action=compose&cust_id=".$_GET['cust_id']."");
        exit;
    }else{
        header("Location: $COMM_PATH");
        exit;
    }
}else{
    $host = $_POST['_host'] ? $_POST['_host'] : $CONFIG['default_host'];
}
So the user is logged into RC automaticaly, user's mail, password and imap server are stored in the database.
Hope this can help you ;-)

2006/11/7, Alexis Domjan <adomjan@horus.ch>:

On Wed, May 31, 2006 at 12:04:31PM -0400, Brett Patterson - Roundcube Forum Admin wrote:
Hello again,

> >I would like to make a login window to roundcubemail from a static page.
> >Is it possible ? According to the login source page there is an _auth
> >value set dynamically, for this reason I can't create a login window on
> >a static page of our website. Is there any solution ?
> Search the forum... it's been asked and answered in a multitude of ways...

I searched the forum but didn't find anything about that specific
question. Actually someone answered me that this question has been
answered before a crash of the forum database.

So where could I the information about creating a login form to RC from
another page ?

Thanks again in advance for your help,
regards,
--
Horus Networks Sàrl
http://www.horus.ch
Responsable technique
Alexis Domjan < adomjan@horus.ch>

--
LOBORAMA
Julien Renouard
julien@loborama.com