But that example will pad an 0 left or right and will make VMs 10-99 as 010 ,, 099

That is completely incorrect. You haven't even bothered to try it, have you?

#!/usr/bin/env perl
use strict;
use warnings;

print sprintf "%02d\n", $_ for (0..20);
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I am not sure how to use the pad_len, $num in my code. I tried it the below way and it did not work. $OPinst = sprintf("%0*d/PMOSS_SIPNBVQM_5MIN_OHDR_$YYYYmmddHHMMSS$digits");

Here is an example of a couple of methods of implementing a similar task to what you are trying.

use strict;
use warnings;

# here is an example that shows how to merge three sub-strings (some o
+f which are variables) along with one number that is hardcoded to 2 d
+igits
my $YYYYmmddHHMMSS = "20220429012345";
for my $num ( 0, 1, 9, 10, 11, 19, 20 ) {
    my $string = sprintf "%s_%s_%s_%02d\n", "prefix", $YYYYmmddHHMMSS,
+ "suffix", $num;
    print $string;
}

# here is an example that shows how to do a similar merge, but making 
+the number of digits rely on a variable, rather than being hardcoded 
+into the format string
for my $num_digits ( 1 .. 4 ) {
    for my $num ( 1, 22, 333 ) {
        my $string = sprintf "%s_%s_%s_%0*d\n", "new_group", $YYYYmmdd
+HHMMSS, "suffix", $num_digits, $num;
        print $string;
    }
}
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This will output

prefix_20220429012345_suffix_00
prefix_20220429012345_suffix_01
prefix_20220429012345_suffix_09
prefix_20220429012345_suffix_10
prefix_20220429012345_suffix_11
prefix_20220429012345_suffix_19
prefix_20220429012345_suffix_20
new_group_20220429012345_suffix_1
new_group_20220429012345_suffix_22
new_group_20220429012345_suffix_333
new_group_20220429012345_suffix_01
new_group_20220429012345_suffix_22
new_group_20220429012345_suffix_333
new_group_20220429012345_suffix_001
new_group_20220429012345_suffix_022
new_group_20220429012345_suffix_333
new_group_20220429012345_suffix_0001
new_group_20220429012345_suffix_0022
new_group_20220429012345_suffix_0333
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If you need to, play around with the example, and see if you can figure out a sprintf command that will do 5 digits. Or one that will merge the strings in a different order. Once you've played around some, and understood what this code is doing, then try to apply it to your own project.

update: also, maybe you didn't know, but the page sprintf describes what everything means, including %d vs %2d vs %02d vs %0*d. You should try to read and understand that page. It will really help you.

Generic advice:

If you are unable to learn from this example and apply it to your own project (or, for that matter, from many of the other examples that have been given you throughout this discussion -- I don't claim mine is the ultimate of examples for learning from), then you need to find a "Beginning Perl" course (either video or text-based), and work you way through that, making sure you understand each individual step, until you have learned the variable and string manipulation skills to be able to understand the examples that your fellow Monks have been giving you in this discussion.

You need to get to the point where you can learn from other examples, even if they aren't matching your exact text -- otherwise, you are not writing the code, you are begging others to write snippets for you, then maybe you are trying to glue them together, and hoping it works. You will not be successful in this project or in any future projects if you are unable to apply the examples that you have been given to situations that don't exactly match what you need.

$digits =~ s/^(\d)$/0$1/;  # add leading zero if only one digit
                           # 0->00  1->01 2->02 etc.
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