If you're desperate for this right now, you can use the Omega Core plugin which has true 3D positional sound so your sounds fade as you move away from the source and you can tell which direction they come from in 3D space. It currently only works with .wav files, but you can also use it to play 2D music. And there's no limitation on number of sounds. You just need to learn how to script loading/playing these sounds in Lua.
System Specs: OS - Windows 7 Home Premium 64-bit SP1, CPU - AMD Phenom II X4 945, 3.0Ghz, RAM - 8Gb DDR3, GFX Card - 2048MB NVIDIA GeForce GT 640, FPSC-R Version - Beta 1.0085
