How to create a save button in record producer to save attachment uploaded in the attachment field

[cjhizon26]

I am trying to create a customized record producer for the task that will have a save button in portal. User can save the uploaded attachment and also submit it. By saving, once user comes back, uploaded attachment is there in the field.

[Uncle Rob]

"Coming back to" isn't something Record Producers are built for.  They're like the construction mechanism for a record, but once the record is created, the record producer itself isn't useful.  

What's preventing them from using the conventional form/portal interface post-submission?