v1.0 of plugin: "Handy File Find and Replace is a free tool meant to assist you to quickly find and replace text in as many text (txt, html, xml, php, asp, perl, js, css, c++, pas etc.) files as you want! Case sensitive Find and Replace, Diverse File Filters, Different Search Attributes, Robust Regular Expressions with extended syntax give you full control over complex text processing in all the desired files with a few clicks. Ability to create HTML listings of files which contain text fragments makes it highly valuable tool for web masters and web coders! HFFR is free." *(Remember that this should only be used on "plaintext"-type files and not special documents like Word/Excel, etc.)
Their information page with colored regular expression tables is available in the files\ folder as "hffr.htm" (not to be confused with this help file), but not added to the XML menu file. You would have to edit in your browser plugin to point to the file if you wish. Otherwise, the TXT-converted version is available from the menu.
Silverage Software site (Full plugin, no other downloads needed.)