Adobe’s Bridge application has a very handy built-in file renaming utility. If you need to add a suffix, a numeric prefix or do a simple string substitution it’s ready and waiting just a keystroke away…

But for more complex string substitutions regex (from REGular EXpressions) come to the rescue!

Here’s a simple problem – you need to rename the first 6 characters of a series of files with a consistent file naming convention…

Fire up the batch renaming dialogue ([SHIFT]+[CMD]+R on a mac) – it’s under the Tools menu. Select your files, choose String Substitution from the dropdown, and check Replace All and Use Regular Expression as in the screenshot below.

The magic regex is in the Find field:
^.{6}

Adobe Bridge Regular Expressions

Explained

The “^” (a caret AKA “up-arrow”, “chevron”, “control character”) denotes the beginning of the search; the dot “.” denotes any kind of character and finally the “{6}” means six of.

Easy peasy.