I'm not sure exactly how you want to select the text, but here is one way:

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

my $word = Win32::OLE->new('Word.Application');
$word->{Visible} = 1;
my $document=$word->Documents->Add;
$word->Selection->TypeText("Some Text");
$word->Selection->HomeKey(wdLine);
$word->Selection->EndKey(wdLine, wdExtend)
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P.S. You can easily findout what you need to do by using word's record macro feature.