Constant 5V power

I am trying to modify my marlin config file to remotely be able to turn on my 3d printer. The problem is that because I use a computer power supply, I have to activate it separately by connecting two wires. I would like to use a transistor to be able to turn it on from the console if my printer is connected. While I can work out the circuitry later, what I need is a 5 volt power that I can toggle on so it can activate my power supply.

Is there any way I can modify the marlin file to be able to provide this type of customization?

Search for PS ON

Power your aruduino via the 5VSB from the power supply. Connect the green wire to the PS_ON pin, and the normal 12V and ground connections to the main power connectors on the RAMP board. Issue M80 to turn on the full power and M81 to turn it off. Your arduino remains always powered via the 5VSB but it's almost a negligible amount of power consumption.