How to use programs using wired modems on monitors

So I have a basic train system (gets redstone signal from indicator rail and shows text on a monitor.) But my question is:
How can I use the wired modem to show that program (named train) on a monitor?
Ex: I have a monitor connected to my computer using wired modem. How I run programs on the monitor?

I'm unsure what you're asking if you want to output to a monitor that is wired you do

mon = peripheral.wrap("monitor_x")
mon.write("Hi")

If you are saying your want to display the computer screen on the monitor you would do something like

term.redirect(peripheral.wrap("monitor_x"))

If you have a new enough version of CC, you can use the monitor program to display on a monitor without redirecting.

monitor monitor_x programName

Where 'x' in monitor_x represents the number of the monitor displayed in chat when activating the modem attached to the monitor.