Arduino PC Power Control

Hello, I am wondering if it is possible to use a UNO to short the PC power pins in order to turn on/off a computer using Google Mini. Sending the web request should be no problem through IFTTT. My main question is how do I provide ground/negative to the PC power pin(PSW+) using the UNO. I would set the pin to output. Then set it to high. When I would want to switch the power to the computer on/off I would then set the pin to low. Am I correct in my reasoning? I want to double check putting the pin output on high. Will this cause current or keep the circuit open until I switch the pin low. I plan on testing the circuit with a multimeter to be sure. The powersw+ is a 5V signal that is switched momentarily in order to turn the computer on/off. Any help would be much appreciated. Thanks.

Yes it is perfectly feasible and either an optoisolator or a simple relay would do the trick. Better to keep the two items electrically seperate if you can.