For any custom import that will be made just once, we made a PHP scripts that read data from existing datasets (database, export files), and adds them directly using RecordBrowser.
Here is a sample file header to load EPESI modules and functions:
define('CID', false);
require_once('/path_to_epesi/include.php');
ModuleManager::load_modules();
// set time limit to unlimited, because import may take some time
set_time_limit(0);
// set user to the first admin
Acl::set_user(1);
// Run custom code here
$rs = new RBO_RecordsetAccessor('contact');
$rs->new_record(array('first_name'=>'00test'));
Adjust path to the EPESI, and add any necessary code. It's better to run such scripts locally from the shell, not by the http server.
Regards,
Adam