@Muhammad-Nihal-Naseer ,
Unfortunately, your example data (both before and after) wasn’t good enough to clarify what you wanted.
There are lots of regex that will do what you want on that specific piece of data. But until you define what you actually want under multiple conditions, it will be impossible to make you happy.
For example,
Is Ns what causes it to be “a particular row”
Is it possible for there to be “a particular row” that has something other than five numbers
Are all your numbers single digits? Or can some of them be multiple digits (like Ns 0 11 2 33 4444)?
Are there any spaces before the Ns?
Are those spaces or tabs between columns?
The best advice for asking for search/replace help is to give a block of data, showing both things that change, and things that should stay the same.
For example,
Ms 0 1 2 3 4
Ns 0 1 2 3 4
Ps 0 1 2 3 4
would work (by my definition, based on my interpretation of your incomplete spec) with
FIND = ^(Ns) \d \d \d \d \d
REPLACE = $1 1 1 1 1 1
SEARCH MODE = Regular Expression
ending up with
Ms 0 1 2 3 4
Ns 1 1 1 1 1
Ps 0 1 2 3 4
… but it would do nothing to the text
Ms 0 1 2 3 4
Ns 0 11 2 33 4444
Ps 0 1 2 3 4
Assuming the rule is “match a line starting with Ns followed by 5 integers of 1 or more digit each”, the FIND would be ^(Ns) \d+ \d+ \d+ \d+ \d+ and the REPLACE would be as I described above. That updated FIND would then turn the “do nothing” text the same way my original did.
But it all depends on what your real data looks like.
----
Useful References
Please Read Before Posting
Template for Search/Replace Questions
Formatting Forum Posts
Notepad++ Online User Manual: Searching/Regex
FAQ: Where to find other regular expressions (regex) documentation
