You can accomplish this by using the s/// replace function: 
my $text = "I saw the panda myself,\nbut Amy did not.\nA var a.my";
my $regexp = qr/(a[ .]*my)/i;

$text =~ s/$regexp/'~'.uc $1.'~'/ge;
print "$text\n";

[download]
gives 
I saw the pand~A MY~self,
but ~AMY~ did not.
A var ~A.MY~

[download]
Here, I have tested for optional spaces and periods. Generalization to other punctuation is straightforward.

-Mark

In reply to Re: Text markup confusion by kvale
in thread Text markup confusion by paurus

Title:
Use:  <p> text here (a paragraph) </p>
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