Custom Webmail login form directly to Roundcube

[diogo_plta]

Accessing http://webmail.domain.com/3rdparty/roundcube you'll open the roundcube directly after login.

The login form of above URL have a hidden input out of the form:
<input type="hidden" id="dest_uri" value="/3rdparty/roundcube" />

But when I try to use this dest_uri var in a custom login form, action to 'domain.com:2095/login', it don't redirect.

How to use this dest_uri var to create a custom login form to redirect to /3rdparty/roundcube?

For example sending by GET or POST and did'nt work:

<form id="login_form" action="http://DOMINIO:2095/login?dest_uri=/3rdparty/roundcube" method="post" target="_self">
<input type="hidden" id="dest_uri" value="/3rdparty/roundcube" />
                            <div class="input-req-login"><label for="user">Endereço de e-mail</label></div>
                            <div class="input-field-login icon username-container">
                                <input name="user" id="user" autofocus="autofocus" value="" placeholder="Digite seu endereço de e-mail." class="std_textbox" type="text"  tabindex="1" required>
                            </div>
                            <div style="margin-top:30px;" class="input-req-login"><label for="pass">Senha</label></div>
                            <div class="input-field-login icon password-container">
                                <input name="pass" id="pass" placeholder="Digite a sua senha de e-mail." class="std_textbox" type="password" tabindex="2"  required>
                            </div>
                            <div class="controls">
                                <div class="login-btn">
                                    <button name="login" type="submit" id="login_submit" tabindex="3">Entrar</button>
                                </div>

                                                            </div>
                            <div class="clear" id="push"></div>
                        </form>