Insert module fields to xml-file and uplod to e.g. ftp

Insert module fields to xml-file and uplod to e.g. ftp

Hi,
pls advise: How can I insert - e.g. using a workflow - certain fields (name, email etc.) of a custom module entry to a pre-formatted xml-file and upload it e.g. via ftp (or - if ftp isn't possible - send it to an integration that supports ftp upload) to a folder on my website. Thank you.