Find, Edit and highlite a line Add-in required

[normankong via OfficeKB.com]

Hi

I require a add-in in outloot which can be executed at any time while a email
is open. The Add-in will search for a particular set of characters example "
==" and highlite the entire line with say yellow and replace the " ==" with
say " **".

Does anyone know where I can get a addin that can do the above.

example

== December 04 2006

addin will change the "==" to "**" and highlight the entire line yellow

** December 04 2006 (<<<<<yellow highlight)

Thanking you in advance

Norman