Is there a method to combine two or more textures to obtain a single one?

Question

Im trying to make a "minecraft-clone" game, i have already done a a chunk system and in this chunks spawns blocks but they are all magenta (the color you have when there is no texture applied on the mesh), as the blocks in the chunk will not be all the same i want to assign their texture via script, like: the block at coordinate x0, y0, z0 to have a specific texture, the block at coordinate x0 y0, z1 has another texture. I thought that i may can try to take the first texture and taking the second one and creating a new texture that has the first texture and the second texture next one by one it would work but i have never did something like this before so i dont know what to do