Yes, there is a way to do this, but the easiest way is to have a second computer.
One computer uses your dj software of choice to play the music. Your pre-amp information goes to your mixer or amp or whatever you use, but you should send the pre-amp music also to the line-in of the second computer. The second computer will use winamp to run AVS with the line-in music after you have set it up using this tutorial
(<--click). This second computer connects to your projector, monitor, or TV to show your visuals.
AVS likes to crash a lot, a crash so fatal that it renders winamp useless until a complete computer restart. This setup I have suggested will avoid the silence or "dead-air" associated with a crash, since the AVS computer isn't actually the one playing the music. The music computer will continue the music even if the AVS computer crashes. If you get sick of the crashes, use milkdrop, which is still a pretty good vis program (although I still like AVS a bit better). Milkdrop crashes a lot less often. It doesn't really crash at all really unless you mess with it a lot.
This is how I've always done it, and it's safe and effective. Just make sure you have a strong enough projector if you plan on using one, as most will look dim if you use a gig-sized screen or surface/wall. When I use school projectors on a gymnasium wall for this at dances, they aren't strong enough to look good, so I have to use my own.
Please post back to let me know how things work out.