Have you tried codex.wordpress.org/XML-RPC_Support.
This code works, in conjunction with the IXR library found at incutio:
include('IXR_Library.php');
$usr="theusername";
$pwd = 'thepassword';
$xmlrpc="http://not-therealurl.com/xmlrpc.php";
$client = new IXR_Client($xmlrpc);
$client -> debug = true; //optional but useful
$params = array(
'post_type' => 'post',
'post_status' => 'draft',
'post_title' => 'Test Post',
'post_author' => 4,
'post_excerpt' => 'This is my test excerpt',
'post_content' => 'This is my test post. Now its longer than the excerpt.'
);
$res = $client -> query('wp.newPost',1, $usr, $pwd, $params);