using hook_node_submit to create an alternate upload method We have a problem where we are uploading a number of files on a regular basis, the files need to be kept outside of the document root. 

Each file is attached to a node.

I created a folder /documentstore and all the files are uploaded to there.

To enable submission of documents I added a symlink sites/default/files/documentstore -&gt; /documentstore

Unfortunately drupal does not allow files uploads to a symlinked folder :( I have modified core to solve the issue as a temporary fix.

For a more permanent fix I'd like to add a module hook node submission and then copy the file to the symlinked folder avoiding drupals core upload function. I am trying to use hook_node_submit().

I would like some hints as to how I can go about this or whether there is a better way to store files outside of the docroot (yes it must be done that way)
Please use the copy function to store the files to different location other than drupal root or files folder.

Alter hook_node_submit function using copy instead of file_save_upload.

Try referring Drupal S3 module code, which copies the files to AWS S3 storage.