Tracing dashboard publish settings from input form in WordPress

Tracing dashboard publish settings from input form in WordPress

I need to replicate a plugin's input form from the dashboard and make it
available to the public so that they can enter data directly to the DB
rather than using a form that is emailed and then copying and pasting it
manually.
Once submitted, rather than publish, I need the entry to sit in draft mode
rather than being published as we need final control over what is
published.
What is the best way to trace the submission of a plugin's publish
settings back to the DB?
Is there a standard function every post entry hits to submit to the DB in
WordPress or is it different for every plugin.
Many thanks.