See perlre and perlrun for documentation. Replace the 13 with other n as required.

your command works perfectly.any clue how to write this command in a script ?

any clue how to write this command in a script ?

Sure, that's an FAQ.

Let Perl (well B::Deparse ) eplain it to you:

perl -pi -e "s/^(.{13})/$1:/;" -MO=Deparse
BEGIN { $^I = ""; }
LINE: while (defined($_ = <ARGV>)) {
    s/^(.{13})/$1:/;
}
continue {
    die "-p destination: $!\n" unless print $_;
}
-e syntax OK
[download]

L*

There are no rules, there are no thumbs..
Reinvent the wheel, then learn The Wheel; may be one day you reinvent one of THE WHEELS.

please tell me in format of script...all i am doing is inside a script. Unfortunately i am not much familiar about how to use commands inside perl script.

"Unfortunately i am not much familiar about how to use commands inside perl script."

This would be a good place to start: perlintro: Perl introduction for beginners

This document will lead you through the creation of a Perl script. It's not particularly lengthy and shouldn't take you long to read. Each section has links to more detailed information: follow as necessary.

— Ken

I am pretty new and I was wondering about this too. I asked the question on the chatterbox and this is the result.

[JobC]    I occasionally read the questions and answers posted on SOPW
+. Often I will see answers that show how to do something from a comma
+nd line. How can this then be converted to a script?
[shmem]    essentially you put the quoted text after -e into a file
[MidLifeXis]    Which platform?
[JobC]    Like this one: in file insert character in every row on nth 
+position
[JobC]    i am using strawberry perl on windows
[MidLifeXis]    There may be some nuances based on Windows/Unix(sh,ksh
+,csh,zsh)/VMS, and so on.
[MidLifeXis]    Is your environment set up to run .pl scripts on click
+?
[JobC]    I have never tried that. I am using cmd shell
[MidLifeXis]    If you do SET PATHEXT, is .pl in the provided list?
[shmem]    then you add a line # *perl * at the top and add switches a
+fter perl
[MidLifeXis]    perl -Mlib1 -Mlib2 -e 'foo(bar())'
[JobC]    nope .pl is not there.\
[shmem]    shmem fades out
[MidLifeXis]    Then just do as shmem is saying, and execute: perl scr
+iptname.pl
[MidLifeXis]    My example above would go into foo.pl as "use lib1;\nu
+se lib2\nfoo(bar());\n" (replace '\n' with a newline)
[JobC]    Ok, Thanks!
[MidLifeXis]    Recommendation: always (or at least until you know why
+ you shouldn't) use use strict; use warnings at the top of your scrip
+t.
[MidLifeXis]    Helps to catch very comment typos and mistakes.
[MidLifeXis]   *common, not comment
[download]

hopefully this helps you as much as it helped me

It might be done with something like substr EXPR,OFFSET,LENGTH,REPLACEMENT:

c:\@Work\Perl\monks>perl -wMstrict -le
"my $s = 'abcdefg';
 print qq{'$s'};
 ;;
 my $char = 'X';
 my $n = 3;
 substr $s, $n, 0, $char;
 print qq{'$s'};
"
'abcdefg'
'abcXdefg'
[download]

Update: Changed example code to make position of insertion a variable.

If followed, your line would be:

cc-20,dd:-kk:jj,01,cc
[download]

UPDATE:The OP updated the original node without explanation/annotation. That removes the context for this node.

YES,

Here is the sample data

2016-02-06-0240:00
2016-02-06-0540:00
2016-02-06-0740:00
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expected output

2016-02-06-02:40:00
2016-02-06-05:40:00
2016-02-06-07:40:00
[download]