First, check How to use buttons and scripts from this forum for how to use the commands below.
Make a button with a command like:
Copy "C:\My Files\File 1.txt" HERE
Copy "C:\My Files\File 2.txt" HERE
Copy "C:\My Files\File 3.txt" HERE
Or use wildcards in the filename to match multiple files:
Copy "C:\My Files\File *.txt" HERE
Or copy the whole folder to the current directory:
Copy "C:\My Files\*" HERE