PHP ldap_add function to escape ldap special characters in DN syntax

I'm trying to add some users to my Ldap DB but I get some errors (invalid dn syntax) when I use some special characters like ",.". I need a function that escape all characters. I try preg_quote but I get some errors in some cases.

Thanks in advance

Code:

$user = 'Test , Name S.L';

    if(!(ldap_add($ds, "cn=" . $user . ",".LDAP_DN_BASE, $info))) {

            include 'error_new_account.php';

    }