Well I know it's not a mouse program but if you're only really interested in using the mouse for casting AoE there is a neat trick that could work for you.

Open keybindings and bind a key to "interact with mouseover"
Bind a key to the Blizzard spell on your bar
Set the cameras to look in about the same direction from overhead.
Hit the blizzard key, then interact with mouseover, and they will cast blizzard.

Hope it helps a little and good luck finding some software to make it a touch more precise