trouble populating input box

Hello,

I can now get data input into the HTML editor input box to be stored in the database.
Before I disappear down a rabbit hold and try to code the "obvious" from scratch, is there some simple way to:
(a) get the input box to load up with any current data stored in the database (e.g. for further review/editing) when a user first logs in (for a new session)?
(b) placing any updated versions immediately back into the input box so people can simply continue editing?

Both can be done in PowerMessenger, and it seems so obvious that I fear I have missed some checkbox or similar to allow this.

Where might I find the code for these two events, and before I struggle with jury-rigging something myself?

Thank you,
KAB

(If you want to see the specific page, I will put it in the upcoming private area in the reply to this).