Open Windows Explorer and go to: "C:\Program Files\Winamp\Plugins" here you will find GEN_CDG.DLL & GEN_CDG.INI. The DLL file generates the lyrics window and the INI file stores it's size and position. Make a copy of GEN_CDG.DLL and call it GEN_CDG2.DLL (you may have to copy it to a different location, then rename it and move it back to the original location), restart Winamp and play a karaoke track, you now have two lyrics windows - one on top of the other, drag the top window to a different position then go to Winamp Options / Preferences / General Purpose, you will see that you now have two CDG Plugin entries, click one of them then click Configure.
Hope this helps.