It's not complicated, don't worry.
Basically, you have your base layer and your glowing layer.
The base layer is what you normally work with, the file with the eye and teeth that you colour however you want. You'll end up calling this something like preset_1eye.png.
You'll want to make another layer overtop. In Photoshop (or whatever you use) create a new layer, and draw your eye (or whatever you want to glow). It helps if you make it a bright colour, and perhaps have a light glowy effect around the eye area on the head.
Hide the other layers so you have just your eye layer and a transparent background, and save this eye layer as a separate file. You can name it something like preset_1eyeglow.png.
Then in the .material file of your preset folder, scroll down to where the eye coding is and put what I paste:
{
technique
{
pass
{
ambient 0.5 0.5 0.5
cull_hardware none
cull_software none
texture_unit
{
texture preset_7eye.PNG
}
}
pass
{
emissive 1.0 1.0 1.0
scene_blend alpha_blend
texture_unit
{
texture preset_7eyeglow.PNG
}
}
}
}
under each eye section, but change the filenames (preset_1eye.png) to whatever you saved the files as.