Regular expressions can be used to find text patterns within an open document or in multiple files. A regular expression is a pattern of text that consists of ordinary characters, or literals, (for example, letters a-z) and special characters, known as metacharacters. The pattern describes one or more strings to match when searching text.
To use regular expressions:
1.Select the Find (to find text patterns in the current file), Replace (to find text patterns and replace them), or Find in Files option (to find text patterns in multiple files) under the Search menu.
2.Check the Use Regular Expressions box and any other search parameters like Match Case.
3.Enter the regular expression to search for and click Find. If using Find in Files, also enter the file type(s) (separated with a semicolon if more than one) and the folder(s) to search. If using Replace, also enter the text to replace the found text pattern with (back references can also be used - see below).