You might also like to look at extending the regexp syntax

I thought about this, but didn't have any experience doing so. I just went with what I know, but I may take a look at your code, and see how it works.

It copies the contents of the last closed capture into the scalar variable named 'name'

I'm not sure I like this part. The idea of extending regular expression syntax is nice, but storing the matches in arbitrary scalars seems a bit sloppy. Maybe this can be reworked to store the results in a hash.

Something along the lines of:

use re 'eval';
use strict;

my $re = convert('(foo)\C{ foo }');

my %hash;
"foo bar" =~ $re;

print $hash{foo}, "\n";

sub convert
{
    my $re = shift;
    $re =~ s( \\ ( \\ | C\{ (?>\s*) ((?>\w+)) (?>\s*) \} ) )
            {
                defined $2
                ? "(?{\$hash{$2}=\$^N})"
                : "\\"
            }xeg;
    $re;
}
[download]

This is only marginally better, though, because instead of clobbering any arbitrary number of scalar variables, it clobbers one hash. Maybe there's a cleaner way to handle this.