Just create CPAN/Config.pm yourself and put it in a place where it loads before any other CPAN::Config. As long as Perl finds it and it's not missing configuration data, CPAN won't start its interactive configuration. The CPAN::HandleConfig::load method is your map to doing it yourself and avoiding the interactive configuration.

The CPAN::Config module itself is just an anonymous hash, so you don't have to do that much work to create it yourself. Create the hash with the local values and dump it:

$CPAN::Config = {
  'build_cache' => q[10],
  'build_dir' => q[/Users/brian/.cpan/build],
  'cache_metadata' => q[1],
  'cpan_home' => q[/Users/brian/.cpan],
  'dontload_hash' => {  },
  'ftp' => q[/usr/bin/ftp],
  'ftp_proxy' => q[],
  'getcwd' => q[cwd],
....
  };
1;
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