use strict;
my $str = 'Bundle can be downloaded at : http://*/downloads/52aa233b-5db4-2298-5e1b-f510b2cd149f/configBundle-ESXi-X10SRH-CF.tgz';
my $regex = qr/^(Bundle can be downloaded at : http:\/\/\*)(\/downloads\/[[:xdigit:]]{8}-[[:xdigit:]]{4}-[[:xdigit:]]{4}-[[:xdigit:]]{4}-[[:xdigit:]]{12}\/configBundle-.+?)(\.tgz)$/mp;
my $subst = '/scratch$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