-----------       ------------           -------------    
|excel     |     |           |           |           |
|template  | <== | callback  |   <====   |database   |       
|          |     |           |           |___________|
|          |     |           |
---------        |___________|   <=====  -------------
                                         |            |
                                         |DCOM server |
                                         |            |
                                         --------------

##</code><code>##

sub cell_walk{
	my $self = shift;
    my ($sheet_name, $x, $y, $callback) = @_;
       
   	my $Sheet = $self->{ 'book_handle' }->Worksheets($sheet_name);
	for ( $row = $x->[0] ; $row <= $y->[0] ; $row++ ) {
    	for ( my $col = $x->[1] ; $col <= $y->[1] ; $col++ ) {
			  $callback->($Sheet->Cells( $row, $col ));
		}
	}

}

sub callback{
     
    return if !defined $_[0]->{Value};
        if ( $_[0]->{Value} =~ /^~~~/ ) {
            my @a =
              split( /__/, substr( $_[0]->{Value}, 3 ) );  #grab useful string
			  if( scalar @a == 3){
            $_[0]->{Value} =
              $hl->get_single_LP( 'ADAS_VAL_RAW', @a );
			  }
			  if( scalar @a == 4){
			$_[0]->{Value} =
			  $hl->accu_LP( 'ADAS_VAL_NORM', @a );
			  }
        }


}