Regex search and replace: 

my $f = "   ";
$f =~ s/^(.{0,5}).{0,5}/${1}12345/;

[download]

The only problem is this regex doesn't pad extra spaces if your string is too short, but at least it still does the replacement.

elbieelbieelbie

In reply to (elbie): substr and strings on the outside by elbie
in thread substr and strings on the outside by JPaul

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