ssh in and run command in pre-existing session?

[Merrattic]

I think this is what I need to do in order to run my script! This is not a gnu-screen question, more a ssh session question (I think?)

Remote machine is a cli only digital picture frame. I use a script on start up to login automatically and then run a script which starts a gnu-screen, inside of which runs the image display and a clock (split gnu-screen )

I can ssh in as the same user and kill the gnu-screen session (screen -x) and the running script, but if I try to run the script again, it doesn't work because I am on the wrong screen/display/tty in my ssh session.

How do I run the script as the pre-existing logged in user (can be the same as the ssh'd user) so that the gnu-screen session appears on the screen/display/tty of the remote machine?