It is possible. See
here. Specifically, note:
Perl String Features in Regular Expressions and Replacement Texts, although Sigil notation is a little different to Perl.
A simple example. Suppose you had the text:
Code:
<h2>chapter two</h2>
The following search and replace:
Code:
Search = <h2>(.+?)</h2>
Replace = <h2>\u\1</h2>
And the result:
Code:
<h2>Chapter one</h2>
Obviously, you can make it as simple or as complex as you like.
Hope this helps.