Here are a couple batch files that can streamline frequently used strings that don't quite justify an AutoHotKey command.

This works for a predefined, on line string. Like a not so important password or address that is used frequently.

echo|set/p=TextToBeCopied|clip

This one is for a formatted block of text stored in a separate text file. Handy for pre-formatted messages and documentation frameworks.

type text.txt | clip