You don't specify what you want this FOR which would be enlightening. What you are describing is sort of asking for a Levenshtein edit distance of 1, but then again perhaps not. These links provide answers/code/modules that may be relevant.

• Text::Levenshtein
• calculate matching words/sentence
• LCCS time complexity
• Algorithm::Diff

Here is a snippet of code that lets you generate a dynamic regex to match you targets. This assumes what you need is as simple as stated.

my $word = 'match';
my $string = 'Hatch a plan to watch this RE match';
my @match_re;
for my $offset( 0..length($word)-1 ) {
    my $possibility = $word;
    # replace one char with . to match anything
    substr $possibility, $offset, 1, '.';
    push @match_re, $possibility; 
}
my $match_re = join '|', @match_re;
print "The match RE is qr/$match_re/\n";
$match_re = qr/($match_re)/;
my @matches = $string =~ m/$match_re/g;
print "Found @matches\n" if @matches;

__DATA__
The match RE is qr/.atch|m.tch|ma.ch|mat.h|matc./
Found Hatch watch match
[download]

Note I am substituting a . into the possibility which will match anything but a newline in the form given. You may want A-Za-z or \w or whatever.....

cheers

tachyon

s&&rsenoyhcatreve&&&s&n.+t&"$'$`$\"$\&"&ee&&y&srve&&d&&print