How to redirect logs from Universal Forwarder to an specific created index different from main index

Hi, Im trying to redirect all logs from a folder in a forwarder to "just" an specific index that we created on the indexer. This is our own create index and we want index the logs from that folder in the forwarder "just" on our index, not on the main index. There is a little confusion here. I have checked some information on the internet and nothing works until now. When somebody says "do something on the inputs.conf" is never clear what to exactly do in that file and "where in that file" (at the begining?, at the end ? in the middle ? at random ?). It is also never clear to which inputs.conf we should add "this something". Because there are several files "inputs.conf" in different paths. And we even have this file in the forwarder and in the indexer. Basically I dont have any clue of "what to add" and "where to add it"(location of the file/files and where within the file). I have tried several things and nothing works. Precise and accurate help will be very much appreciated. Thanks !