C4DtoA has built-in support for the C4D Substance Shader which allows users to access a specific channel (texture) of a Substance asset (.sbsar).
No extra step is required to work with a Substance asset in C4DtoA. Just create a Substance Shader, load a Substance asset and drag & drop it to the Asset field from the Substance Asset Manager. The available channels are then listed in the Channel combo box.
C4DtoA writes the substance textures to the tex/substance_cache folder of the project. The file names are [substance_name]_[channel_id].tif. These textures are then read by Arnold during the render. If the scene is not yet saved, the textures will be written to the system temp folder.