Picture location based on var?

Hello everybody! I am looking for a simple -Yet, maybe hard- plugin to make. Perhaps not even one, and just a plain JS code.

Thing is: I am trying to recreate a "Candle" on my game hud. The wax is a gauge that diminishes every second, but there is no fire! I was looking for a way to insert an image of a fire at the top of the candle that every second would refresh its location to
the top of the gauge i use as the candle body.

Here's an example of what i'm trying to do: