use strict;
use warnings;

use re q{eval};

my @numbers = (
   q{Number... ()},
   q{Number... (1)},
   q{Number... (12)},
   q{Number... (123)},
   q{Number... (1,234)},
   q{Number... (12,345)},
   q{Number... (123,456)},
   q{Number... (1,234,567)},
   q{Number... (12,345,678)},
   q{Number... (123,456,789)},
   q{Number... (1,234,567,890)},
   q{Number... (1,234a)},);

my $deCommafied;

my $rxNumberGrps;
$rxNumberGrps = qr
   {(?x)
       \D*
       (\d+)
       (?=,|\))
       (?{$deCommafied .= $^N})
       (?:
          (??{$rxNumberGrps})
          |
          \)\z
       )
   };
my $rxDeComma = qr
   {(?x)
       (?{$deCommafied = q{}})
       $rxNumberGrps
   };

foreach my $number (@numbers)
{
    print
       qq{$number - },
       $number =~ m{$rxDeComma}
       ? qq{$deCommafied\n}
       : qq{no match\n};
}

##</code><code>##

Number... () - no match
Number... (1) - 1
Number... (12) - 12
Number... (123) - 123
Number... (1,234) - 1234
Number... (12,345) - 12345
Number... (123,456) - 123456
Number... (1,234,567) - 1234567
Number... (12,345,678) - 12345678
Number... (123,456,789) - 123456789
Number... (1,234,567,890) - 1234567890
Number... (1,234a) - no match