I have piped responses in various batch scripts on this site, but if you were trying to search for the 'how to', you may not find them.
Here are 3 solutions:
1. Some commands have a switch (/Y) which eliminates the prompt. It may not even be documented.
2. Example for responding to a prompt from the output of a command:
echo y | <command>
3. Example for responding to a prompt with the contents of a text file: