http://[your-domain-here]/index.php?option=com_cck&view=form&layout=edit&type=user&id=[id_of_any_user]

<?php
define( '_JEXEC', 1 );
define('JPATH_BASE', dirname(__FILE__) );
define( 'DS', DIRECTORY_SEPARATOR );
require_once ( JPATH_BASE .DS.'includes'.DS.'defines.php' );
require_once ( JPATH_BASE .DS.'includes'.DS.'framework.php' );

$mainframe =& JFactory::getApplication('site');
$mainframe->initialise();
$mainframe->route();

$user =& JFactory::getUser();
$usrid = $user->get('id');
$grparray = $user->get('groups');

$sum = count($grparray);

for ($i=0; $i<$sum; $i++) {
 $grpid = $grparray[$i];
}
$getGroups = JAccess::getGroupsByUser($usrid);
$sum2 = count($getGroups);

for ($i=0; $i<$sum2; $i++) {
 $newgrpid = $getGroups[$i];
}

// Append associative array elements
function array_push_associative(&$arr) {
   $args = func_get_args();
   foreach ($args as $arg) {
       if (is_array($arg)) {
           foreach ($arg as $key => $value) {
               $arr[$key] = $value;
               $ret++;
           }
       }else{
           $arr[$arg] = "";
       }
   }
   return $ret;
}

$urlCCK = array();
foreach($_GET as $key => $value) {
    array_push_associative($urlCCK, $items = array("$key" => "$value"));
}

// IF current user is in the Registered Group and their id is NOT equal to the URL's, then there's a problem.
if (
	($newgrpid         == 2)            &&  // Registered or above
	($urlCCK['option'] == 'com_cck')    &&
	($urlCCK['view']   == 'form')       &&
	($urlCCK['layout'] == 'edit')       &&
	($urlCCK['type']   == 'user')       &&  // e.g. user or applicants, etc.
	($urlCCK['id']     != $usrid)
) {
header('Location: [Add your URL to an Access Denied type page]');
exit;
}