Newbie Virtual pins help needed!

Please help me with the codeing I need to use to push temprature data received from a digital pin to a virtual pin, so I can use the eventer wiget to trigger a digital pin GPIO when the temp either rises above or drops below a set point.
hardware used: RPi 3 + 8ch Relay Board

hello!

probably 99% of the info you need it is here:
http://examples.blynk.cc/

if you hit some roadblocks, please provide what did you done so far, and paste your sketch here, (properly formatted)