File to Proxy with an attachment

Hi,

  I had a requirement , File to Proxy. File should go as an attachment to ECC.

I had gone through the following Doc

Handle SOAP with Attachment in SAP PI 7.31 . In my case Sender is File , i can't take the reference of this doc.

I had tried of attaching the file to SFTP (Additional Files). But its throwing an error with Payload swap bean.

So can any body throw some light how can we attach a file to FTP/SFTP .

Also can ignore the main payload.

Or can we have any other approach to meet the above requirement.

Regards,

Samir