Just call it and pass it the request. A handler is just a sub (and method handlers are just instance methods). There's nothing that says you can't delegate. And if the handler in question could be called directly, have it use the instance() method that Apache::Request provides that will just return the same object no matter how many times during a request it gets called (see the A::R docs for more info).

package Foo;

use Apache::Request;
use Apache::Constants qw( OK );

sub handler {
  my $r = Apache::Request->new( shift );

  $r->pnotes( Foo => "Bar" );

  return Bar::handler( $r );

}

package Bar;

sub handler {
  my $r = shift;

  $r->send_http_header( "text/plain" );

  print "uri is: ", $r->uri(), "\n";

  print "Foo is: ", $r->pnotes()->{Foo}, "\n";

  return OK;
}

1;
__END__

  <Directory /usr/local/apache/htdocs/foo>
    SetHandler perl-script
    PerlHandler Foo
  </Directory>

uri is: /foo
Foo is: Bar
[download]

Update: Ahh, I actually looked back up the thread and saw the sample code that looks similar to this. It looks like you should be using the instance() method in both handlers and that'll always give you back the same A::R object as a singleton. Teach me to read back up the whole thread rather than just looking at replies. %)