Using a timeout with display files

Dear friends:

A few weeks ago, I inquired about something related with the subject, to
which I could achieve what I was looking for.

The goal was to allow the user to type in data on a few display fields
within a given period of time (say 30 seconds). If that period of time
went off, then control is given back to the program and take some actions.
Of course, we're talking about an RPG program here.

Now, since there is no key pressing in this scenario, the input buffer is
then NOT updated, so whatever the user could have typed in, none of that
can be retrieved.

I've been asked to find out a way to keep that typed in data and have it
back to the program as though the user pressed either Enter or another
function key. Much the same as the attention keys, I know no input buffer
is updated when giving control back to the program. That is what the user
does NOT want.

So, is there any way to force the system like "hey, after 30 seconds, could
you please pretend the Enter key or (say) F6 key was pressed, so as to have
any typed in data available to the program?"

Is that possible? If not, any ideas on how to get that approach?

Thanks in advance.