Writing custom InfluxQL functions?

Hello all. I tried googling this question but found nothing. My question is, it it possible to create my own InfluxQL function? I want to create a continuous query but don’t want to use the functions that they have. The function I am trying to write is simple as taking two values from the same measurement, multiplying them, and then writing them to a new tag. (I.e I have a data value “Current” and a data value “Voltage”, and what I want to do is create a continuous query to calculate “Power” which is Current * Voltage. Is this type of thing possible? Are there any examples that I can refer too? Thanks to all of those who reply in advance.