I want to replace only the superscript numbers alone, but for me all the numbers are changing.

This seems to work:

use Win32::OLE::Const 'Microsoft Word';
use Win32::OLE::Const 'Microsoft Office';
use Constant 'True' => 1;
use Constant 'False' => 0;
#$Win32::OLE::Warn = 2; # Throw Errors, I'll catch them

my $word = Win32::OLE->GetActiveObject('Word.Application') || 
        Win32::OLE->new('Word.Application', 'Quit');

my $mydoc = $word->activedocument; 
my $rng = $mydoc->{range};
$rng->find->clearformatting;
$rng->find->replacement->clearformatting;
$rng->find->font->{Superscript}= msoTrue;
$rng->find->execute({findtext=>"[0-9]", 
        wrap=>wdFindContinue,
        replacewith=>"<sup>^&</sup>",
        matchwildcards=>'True',
        # matchallwordforms => msoFalse,
        replace=>wdReplaceAll});
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