Добавить поле в форму - JoomShopping

<tr>
    <td width = "100"><?php print _JSHOP_FULL_NAME?>:</td>
    <td><?php print $this->order->f_name?> <?php print $this->order->l_name?></td>
</tr>
//Делаете так:
<tr>
    <td width = "100"><?php print _JSHOP_FULL_NAME?>:</td>
    <td><?php print $this->order->f_name?> <?php print $this->order->l_name?> <?php print $this->order->ext_field_1?></td>
</tr>

 <td class="name">

            <?php print _JSHOP_L_NAME ?> <?php if ($config_fields['l_name']['require']){?><span>*</span><?php } ?>

          </td>

          <td>

            <input type = "text" name = "l_name" id = "l_name" value = "<?php print $this->user->l_name ?>" class = "inputbox" />

          </td>

        </tr>

        <?php } ?>

        <?php if ($config_fields['f_name']['display']){?>

        <tr>

          <td class="name">

            <?php print _JSHOP_F_NAME ?> <?php if ($config_fields['f_name']['require']){?><span>*</span><?php } ?>

          </td>

          <td>

            <input type = "text" name = "f_name" id = "f_name" value = "<?php print $this->user->f_name ?>" class = "inputbox" />

          </td>

        </tr>

        <?php } ?>

        <?php if ($config_fields['m_name']['display']){?>

        <tr>

          <td class="name">

            <?php print _JSHOP_M_NAME ?> <?php if ($config_fields['m_name']['require']){?><span>*</span><?php } ?>

          </td>

          <td>

            <input type = "text" name = "m_name" id = "m_name" value = "<?php print $this->user->m_name ?>" class = "inputbox" />

          </td>

        </tr>