Save form as the form data from three fields

I'm using Adobe Pro 9.0.0 and LC ES. I am trying to take three fields of data, like: Number, date, and name. Add or merge them together to be placed into a hidden field, then when the user selects the SAVE button I need a script that will get the hidden field data and insert it as the filename to be saved to a specific path. Is this possible in LC ES?