// set the "Where From" URL that appears in the Finder's Get Info window
// #needsFile 

let url = 'https://www.example.com/';
let filePath = event.file.filePath;
let cmd = 'xattr -w com.apple.metadata:kMDItemWhereFroms '

cmd += app.shellEscapeArgument(url) + ' ';
cmd += app.shellEscapeArgument(filePath) + ' ';
let [status, stdout, stderr] = app.runShellCommand( cmd );