This seems to handle the pathological cases? 

#! perl -lsw
use strict;

my @reps = map{ sprintf '%05d', $_ } 0 .. 20;
while(<DATA>) {
    my $n=0;
       # redundant /e option  removed 
       # per [Abigail-II]'s comment below.
    s/\d{5}/$reps[$n++]/g;   
    print;
}
__DATA__
0000000000000000000000000000000000000000000000000000000000000000000000
+0000000000000000
00000xxxx00000xxxxx00000xxxx00000xxxxx00000xxx00000xxx00000xx00000xxx0
+0000x00000x00000

[download]

Outputs

c:\test>234342
0000000001000020000300004000050000600007000080000900010000110001200013
+0001400015000160

00000xxxx00001xxxxx00002xxxx00003xxxxx00004xxx00005xxx00006xx00007xxx0
+0008x00009x00010

[download]

Examine what is said, not who speaks.

The 7th Rule of perl club is -- pearl clubs are easily damaged. Use a diamond club instead.

In reply to Re: repeated replacement regex by BrowserUk
in thread repeated replacement regex by Anonymous Monk

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.