Obtain hardcopy from a screen session

I have a job launched in a screen session which is expected to run for several hours. From time to time I'm requested to check if job is still running and guess at wich % of work is.

Guess if it is working or not is as simple as perform a ps -fu $LOGNAMEto check if the process is still alive, but in order to guess the % I need to check the output of the program (it outputs some information which can be used with grep -n to see which line of file it is currently processing).

I can attach the session (screen -R jobLoadItems) and take a look to it, but I would like to do it without attaching to session again. I already checked to perform inside the screen session Ctrla-H to activate screenlog but it's so verbooooooooose it will take all disk space available.

So there is a way to just print last lines of the screen session without attaching to it? (something like screen -S jobLoadItem -Q display last 50 lines)

You can use

 screen  -r <name of sesion> -X hardcopy

this is same as Ctrla-h

from the man page:

Ctrla-h (hardcopy)
Write a hardcopy of the current window to the file "hardcopy.n".