Accessing to a texture file within cginclude

Does anybody know how to assign a specific texture files to a shader that do not work with material, and access to that texture from it? I am talking about shaders like unitycg.ctgInc.or any internal shader files.

I need the shader helper file to read a look up texture that works globally. But have no idea about how to do it.

Thanks for any help!
James

 

You can set a global texture with this in script;
Shader.SetGlobalTexture("_MyTextureVariableName", myTexture);

Then inside your shader you simply call
sampler2D _MyTextureVariableName;

and you can use it like any other texture in your shader.

 

@Farfarer
Thank you so much for this tip!

It is exactly what I need!