From a main_init.cfg you only get the name of the mod, cause they don't have any image like custom stories do, unless the modders start to include them. But it doesn't matter, for IFC/FC we only care for its location, to generate the command string.
By the way, for win users I found a better way to launch Amnesia. Example:
start "" Launcher El Fantasma/Config/main_init.cfg
exit
It opens launcher.exe so players may choose their settings beforehand. And using start "" before calling the executable, opens the launcher without depending on the batch, so it can close itself with exit.
So it would be something like this: start "" $launcher_path $maincfg_path