add file to $_FILES array by reading remote file

I'm pretty new to php and we're trying to write a plugin for wordpress. We have a server with images on it and we'd like to have the plugin have a list of images to download from the server. It then needs to go through that list and read each image from the server into the $_FILES variable that we can then pass to the wordpress media_handle_upload function.

I've been able to read a remote file with the following code. But I'm not sure where to go from here.

$url = 'http://www.planet-source-code.com/vb/2010Redesign/images/LangugeHomePages/PHP.png';

$img = curl_init();
curl_setopt($img, CURLOPT_URL, $url);
curl_setopt($img, CURLOPT_HEADER, 1);
curl_setopt($img, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($img, CURLOPT_BINARYTRANSFER, 1);
$file = curl_exec($img);
curl_close($img);


$file_array = explode("\n\r", $file, 2);
$header_array = explode("\n", $file_array[0]);
foreach($header_array as $header_value) {
  $header_pieces = explode(':', $header_value);
  if(count($header_pieces) == 2) {
    $headers[$header_pieces[0]] = trim($header_pieces[1]);
  }
}
header('Content-type: ' . $headers['Content-Type']);
header('Content-Disposition: ' . $headers['Content-Disposition']);


$imgFile = substr($file_array[1], 1);
echo $imgFile;