use strict;
my $str = 'Colombo: tentio.milenium:02
TestL: u29kae.ee
Restric: free28os
';
my $regex = qr/\w+: ([^\s]*)$\n\w+: ((?1))\n\w+: ((?2))$/mp;
my $subst = '$2:$3@$1';
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