When you do a simple match, you can assign the captured portions to an array like this:

my $str = "foobarbaz";
my @a = $str =~ /(.)oo(.)ar(.)az/;
local $, = ", ";
print @a;

__OUTPUT__
f, b, b
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Given that, you can wrap the match in a qr// and run it twice:

my $regex = qr/(.)oo(.)ar(.)az/;
my $str = "foobarbaz";
my @a = $str =~ $regex;
$str =~ s/$regex/$3$2$1/;
local $, = ", ";
print $str, @a;

__OUTPUT__
bbf, f, b, b
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