my $q = CGI->new( \ &WhizBang::upload_hook, $self );
# where $self is a ref to the current WhizBang object

# then later 
sub upload_hook {
  my  $remote_filename  = shift;
  my  $buffer           = shift;
  my  $bytes_read       = shift;
  my  $self             = shift;
  my  $progress = $self->param('progress');
  my( $filename ) = $remote_filename =~ m/^ (?: .* [:>\]\\\/] )? ( .* ) $ /xs;
  $progress->{file_name}  = $filename;
  $progress->{bytes_xfrd} = $bytes_read;
  $progress->{time_now}   = time();
  # other processing to output data to external storage
  # for display from another script
}