Fluid Tanks and 'floppers'

I am currently using the latest snapshot of MCreator, and am making a mod that involves moving magical fluids from tank-block to tank-block. I am currently working on a fluid-hopper, a 'flopper' if you will, and I was wondering if there was a way to check what fluid was in a block and when to fill another block with that specific fluid. From what I can see, the procedures, you cannot get what fluid is in a tank, and the fill procedures have a drop-down rather than a variable slot.

I would appreciate help solving this problem with the procedure block if possible, but I do have a (somewhat rudimentary) understanding of the Java language, though not in a Minecraft modding context. 

I put my questions to the expanse of the internet, hoping for answers.

-Diskman