You can simply add a class to the menu link e.g.:
<?php
global $mod_strings, $app_strings;
if (ACLController::checkAccess('Accounts', 'edit', true)) {
$module_menu[] = array(
'"index.php?module=Accounts&action=EditView&return_module=Accounts&return_action=DetailView" class="side-bar-Create"',
$mod_strings['LNK_NEW_ACCOUNT'],
"CreateAccounts",
'Accounts'
);
}
?>