All Metal Hot End Fan

Hi Guys,

I have now had my all metal hot end fan in for about a week now, and printing is great, but I have my hot end fan plugged into the ramps board where it says "fan" which seems to be on permanently. I also have a fan cooling down the actual ramps board too, as it was getting really hot, and that is plugged into the spare extruder heating wires (which is controlled via geode)

Now what I want to know is (and i have searched all over for the question), can the extruder fan be controlled via gcode?

I ask this, as I would like to have the fan turned off while the hot end isn't running, and when the hot end does heat up, then the fan should turn on. As the fan is on before the hot end, it seems to cool down my heated bed, which means it takes so much longer to heat the bed up.