RegName is a small yet flexible regular expression based file rename tool. It shows a list of files in a folder matching a selectable pattern. It then allows you to rename those files to another pattern, including preview.
RegName supports both a graphical and a command-line interface.

Renames files using regular expressions.
Usage:
1. RegName [options] "<file-pattern>"
Lists files matching the file-pattern.
2. RegName [options] "<file-pattern>" "<rename-pattern>"
Renames files matching the file-pattern to the rename-pattern.

Arguments:
file-pattern: a regular expression
rename-pattern: the replacement text for matching files

File-patterns contain variables between angle brackets, as in:
<base>.<ext>

Optionally, a variable name can be followed by a semicolon and a regular expression:
<month:[0-9]{2,4}>

The default regular expression is .* which is to say: everything.
A rename-pattern contains the same variables, but always without the regular expression, e.g. <month>

Options:
-s: handle files in subdirectories, too
-x: execute. If not specified, preview only (renaming only)
-v: verbose output
-?: show help text.

The license of this software is Freeware, you can free download and free use this search tool software.