Not sure if I understand, you want to run the command on an already running screen session ?
You can create a new one using screen -dmS NAME Command-sets
And running screen -ls you will have the list of screen running:
There is a screen on:
1661.ushare_screen (02/16/10 08:48:10) (Detached)
1 Socket in /var/run/screen/S-root.
if is detached you can just attach to it.
screen -r 1661.ushare_screen
To detach again press control C and Control D
You just need to script that.
I create a good screen script you can check it here: http://soad1982.blogspot.com/2009/07...search-results