Help with 2 snippets, export and duplicate document

I wrote a script that modifies an OO document into a plist. There are two steps I cannot get working

The first is to copy the contents of document 1 into a new document. I can make a new document, but moving the data is where I reach the limit of my understanding.

Second, this line fails with an error message that I don’t have access:

export document 1 to (DeskSave & ".txt") as "public.plain-text"

My Applescript skills are way weak – I haven’t done anything with them since Sandboxing, so perhaps there is a missing piece to the second issue.

I can do these manually if I have to; but automating them would improve things a bit, assuming its something simple.

Thank you in advance for any advice.