Hi, just include
c instead of a

in your expression 

$input='Cat cat';

$input =~ s#\b([Cc]at)\b#<span class="topic">$1</a>#g;

print $input;
#output
#<span class="topic">Cat</a> <span class="topic">cat</a>

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In reply to Re: case preservation in regexp by perlsen
in thread case preservation in regexp by water

Title:
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