Have you bothered to check the modding section? No?!? Please do. There may not be a mod that is exactly what you want, but there are plenty very close. You could modify the closest to use acid instead of whatever it currently does. That is a supremely easy thing to do.
Here. Take this mod, edit it to use instead of and you have exactly what you want. http://community.gaslampgames.com/t...perborean-enchanting-a-work-in-progress.3815/ You may need to read this page to find the exact spelling as needed. http://dredmod.com/wiki/Spell_Effects http://dredmod.com/wiki/Damage