use strict; use warnings;
use Win32::OLE::Const 'Microsoft Word';

my $file = 'E:\test.docx';

my $Word = Win32::OLE->new('Word.Application', 'Quit');
$Word->{'Visible'} = 0;
my $doc = $Word->Documents->Open($file);
my $paragraphs = $doc->Paragraphs() ;
my $enumerate = new Win32::OLE::Enum($paragraphs);


while(defined(my $paragraph = $enumerate->Next())) {

    my $text = $paragraph->{Range}->{Text};
    my $sel = $Word->Selection;
    my $font = $sel->Font;

    if ($text =~ /Perl/){
        $font->{Bold} = 1;              
    }   
    $sel->TypeText($text);          
}

$Word->ActiveDocument->Close ;
$Word->Quit;