Multiplay can do this easily! I run lights and sound for a Community Theatre and have been using Multiplay for the last 2 years. Solid little application.
Use a Control Cue set up as follows:
START PLAY 2nd sound
Check out Cham Sys MagicQ PC Introduction - On Stage Lighting for a great tutorial on MagicQ PC. Rob has several tutorials on MagicQ PC, and covers it well from setting up your first lights to movers. The Enttec USB-DMX dongle (60USD) works great for my conventional rig. Have used it through...