use strict;
my $str = '78.00600.00 dollars test';
my $regex = qr/^(?=.*\b\d{2}\.\d{2}.*dollars)((\b\d{2}\.\d{2})(?:.*)(dollars)(?:.*))/mp;
my $subst = '$2 $3';
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