If you have FTP access to the remote server you can use fopen with the 'ftp://' style URI
http://www.php.net/manual/en/function.fopen.php
$remote_fh = fopen('ftp://user:password@host/path/to/file.txt','r') or die("couldn't connect to ftp");
$local_fh = fopen('/tmp/file.txt','w') or die("couldn't open file to write");
while($data = fread($remote_fh,1024))
{
fwrite($local_fh,$data);
}
fclose($remote_fh);
fclose($local_fh);
Cheers,
Andy.