multitexturing alpha masking

[floyd6]

I want to texture a quad so it look like this:

http://floyd6.yoyo.pl/gl/out01.jpg

http://floyd6.yoyo.pl/gl/out02.jpg

Having these 3 textures:
http://floyd6.yoyo.pl/gl/p01_mask.jpg

http://floyd6.yoyo.pl/gl/p02_rgb.jpg

http://floyd6.yoyo.pl/gl/p03_rgb.jpg

How do I combine those textures with glTexEnv? What sort of glBlend should I use?
Should these textures be rgba bitmaps or will rgb do as well?

Thanks!

[V-man]

Use shaders and forget about glTexEnv
http://www.opengl.org/wiki/index.php/Multitexture_with_GLSL