Some trouble with multitexture, alpha blend and lighting

I’m trying to do something which looks painfully simple:

draw some quads using multitextures, blending using the alpha in glColor() between texture 1 and texture 2, and light them.

I am just too plain stupid to figure out what the GL_COMBINE_RGB_EXT parameters have to be to get this to work when lighting is enabled. I’ve got it working without lighting.

Any suggestions? I’m sure this must be about as common a situation as is possible with multitexture…