Making tamed animals free roaming after shift + right click

Title pretty much explains it all, I was hoping to make a mod that would let tamed animals not be stuck to your side if you shift and right click them. Seems like a simple task, but I have little to no knowledge with these things.
Figured it should go something like:

upon: shift+right-click
set animal path: roaming

but I do not know the correct format, any help is appreciated!