use strict;
my $str = 'As she did so, a most extraordinary thing happened. The bed-clothes gathered themselves together, leapt up suddenly into a sort of peak, and then jumped headlong over the bottom rail.
It was exactly as if a hand had clutched them in the centre and flung them aside .
Immediately after, .........';
my $regex = qr/[^.?!]*(?<=[.?\s!])was exactly(?=[\s.?!])[^.?!]*[.?!]/imp;
my $subst = '';
my $result = $str =~ s/$regex/$subst/rg;
print "The result of the substitution is' $result\n";
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Perl, please visit: http://perldoc.perl.org/perlre.html