使用WordPress将文件上载到特定文件夹

I need help for how to upload a file in WordPress, I don't want to upload files into the default path of media files i.e. into uploads/../.., I want to upload my files into wp-content/uploads/my_folder, I just created one file in wp-admin folder and added some functionality there, from that form I want to upload my file (not creating plugin).

Is it possible to do like this? If yes then how? If no then what I want to do for uploading file?

I tried the following solution for it:

    $path_array  = wp_upload_dir();
    $upload_path = $path_array['baseurl'].'/myfoldername/';
    $target_path = $upload_path."/".$file_name;
    $file_name = $_FILES['fieldname']['name'];
    $tmp_name = $_FILES["fieldname"]["tmp_name"];

    upload_user_file($_FILES,$upload_path); // Called this function

In functions.php of my theme, I defined the above called function upload_user_file() like as follows:

function upload_user_file( $file = array(),$path) {
    if(!empty($file)) 
    {
        $uploaded=move_uploaded_file($file['fieldname']['tmp_name'],$path.$file['fieldname']['name']);
       if($uploaded) 
       {
           echo "Uploaded successfully ";
       }
       else
       {
            echo "Some error in upload ";
            print_r($file['error']);
       }
    }
}

Please help me for this issue.

Thanks.

It's not working because of FILES array loses its values very soon.. Upload it in the same code where you called function it will work...

Thanks cale_b its really helpful.