If you leave the switch in the ON position (always) then it will always start up when you plug it in. There's no API or GUI control for power on/off.  The web admin allows for restarting only. Here is one suggestion that you may use is the controllable power devices, such as
https://www.amazon.com/Switched-Switchable-Outlets-Designed-Supported/dp/B0039OZKPE
https://www.amazon.com/3Gstore-Remote-Power-IP-Switch/dp/B01GOOE8OY

Please keep in mind these devices from amazon are third party devices. It is the user's responsibility if anything goes wrong by using these devices. 

Note: ThinkRF D4000/R5550/R5750 uses the non-momentary switch.


Keywords: Power Switch, remote control.