No need to switch software as Keyclone does what you're trying to do, though I can't personally vouch for how accurate it is. For ground-target blizzard/flamestrike/volley, it should be fine.

http://www.dual-boxing.com/showthread.php?t=26299

http://www.dual-boxing.com/showthread.php?p=177435

Note that you will need to set your camera zoom and angle the same on all 5 (or all 4 slaves, at least) for it to work effectively.