Need help making translucent texture without using GLSL

i want to make a dome for my unity game like in the sci fi movies and i don’t know how to make it half transparent or translucent using multitexture . i can do it using GLSL but with that option i have problems texturing other objects in my level . also if possible i want to be able to apply an image texture to my dome and make it partially transparent to make it a little better looking . I’ve been struggling with this problem for quite a while , i spent a lot of hours googling it but i stilll don’t get it right :(. any help appreciated