I was able to reproduce the problem in Notepad++ 7.9.2 and I instantly solved it.
How did I reproduce it
Use '(.*)pov\"(.*)Fred(.*)\"$'
(WITH single quotes), it returns error: Find: Can't find the text "'(.*)pov\"(.*)Fred(.*)\"$'"
, which is correct.
![enter image description here](https://cdn.statically.io/img/i.sstatic.net/jnYIK.png)
How did I solve it
Just remove the single quotes and it will correctly find the matches:
![enter image description here](https://cdn.statically.io/img/i.sstatic.net/IKZvh.png)
Explanation
Regular expressions are treated as strings, in PowerShell texts enclosed in quotes ('
and "
) are treated as string objects, in most if not all programming languages
you need to explicitly use quotes to make a segment of text a string object.
However in Notepad++ everything you type is already treated as strings, so the quotes become literal quotes and part of the string, changing the meaning of the regex so there wouldn't be matches.
Update per comment
I tested it myself and I found that you don't need to use fred
(lower-case), Fred
(proper-case) works fine, Notepad++ is case-insensitive.
Proof:
![enter image description here](https://cdn.statically.io/img/i.sstatic.net/s2zmW.png)
'
s from the pattern?