notepad++ using regular expressions for lookup substitution

Using regular expressions can do a lot of tedious and time-consuming work, with the following transcription of the use of editplus regular expressions, as well as for notepad++:
Expression description
\ t tab.
\ n New Line.
. matches any character.
| Matches the left and right characters of an expression. For example, "AB|BC" matches "AB" or "BC".
[] matches any single character in the list. For example, "[AB]" matches "a" or "B". "[0-9]" matches any number.
[^] matches any single character outside the list. For example, "[^ab]" matches characters other than "a" and "B". "[^0-9]" matches any non-numeric character.
* The characters on the left are matched at any time (0 or more times). For example, "be*" matches "B", "Be" or "bee".
+ its left character is matched at least once (1 or more times). For example, "be+" matches "be" or "bee" but does not match "B".
? The characters on the left are matched 0 or 1 times. For example, "be?" matches "B" or "be" but does not match "bee".
^ The expression on its right is matched at the beginning of a line. For example, "^a" matches only lines that begin with "A".
The expression on its left side is matched at the end of a line. For example, "e$" matches only lines that end with "E".
() affects the order in which the expression is matched and is used as the grouping token for the expression.
\ escape character. If you want to use "", you should use "\".

How do I replace linked content with notepad++?

Regular expression: (href=") [^"]* (") replaced by: $1#$2  You can change the contents of the HREF to # and the rest will remain the same. 

notepad++ using regular expressions for lookup substitution