You could try the one from xXx_Guitar, but I prefer the older versions of it. Or have a look at the one in the 3DGS Wiki. It is may a bit slower, but supports up to 6 lights and looks awsome

Slin

Lite-C Tut. 1 Lite-C Tut. 2 Lite-C Tut. 3 (en)
Shader Tutorial (ger)

http://www.slindev.com