element_validate & form_set_value

Hello,

I am trying to have a element level validation update the value of that element in an attempt to correct to what the user might have meant but cannot get the field to be updated. I also want it to throw an error and alert the user, not just update and keep going. The code that should be relevant is below. I can provide more if necessary. Any help would be appreciated.

validator code block (simplified)

 function rm_...._validate($element, &$form_state) {
  ....
         form_set_error('ipaddress','Did you mean "' . $matches[0] . '"? Please verify and resubmit the form.');
         form_set_value($element, 0, $form_state);
  ....
   return $element;
 }

form item

   $form['core']['field'] = array(
     '#type' => 'textfield',
     '#input' => TRUE,
     '#title' => t('Title'),
     '#required' => FALSE,
     '#default_value' => $node->value,
     '#maxlength' => 15,
     '#weight' => 1,
     '#element_validate' => array('rm_....._validate'),
   );