You just mod the game interface to have a crosshair, and then you make it so when you acquire one of those items that shoot things it creates a dummy unit (That's flying, I dunno the height it depends on your camera) and then you move it forward until it hits something.
I do know this - xenforo dropped the ball by not keeping the vbulletin reputation comments as a feature. The loss of the Reputation comments data when we switched to Xenforo really was the death knell for the site when it came to all the users that left. I know I missed it so much and I got way less interested in the site when that feature was gone and I run the site.