How to add index to custom field?

Hi , i have a problems with adding indexes to custom table by array with params like accounts_cstm!
$dictionary[“Account”] = array(
‘table’ => ‘accounts_cstm’,
‘fields’ => //We can added fields here, we must at least have the id_c field
array(
0 =>
array(
‘name’ => ‘id_c’,
‘type’ => ‘id’,
),
),
‘indices’ => // our custom indexes go here
array(
0 =>array(
‘name’ => ‘idx_accounts_phone_c’,
‘table’ => ‘accounts_cstm’,
‘type’ => ‘index’,
‘fields’ => array(‘phone_c’),
),
),
);