Getopt::Mixed::init( 'c=s f=s conf>c foo>f');
while( my( $option, $value, $pretty ) = Getopt::Mixed::nextOption() ) {
  OPTION: {
    $option eq 'c' and do {
      # you want to do more error checking that this...
      eval { do $value };
      die "Cannot load config file $value: $@\n";
      last OPTION;
    };
    $option eq 'f' and do {
      $Foo = $value;
      last OPTION;
    };
    # ...
  }
}
Getopt::Mixed::cleanup();