use warnings;
use strict;

my ($fname) = @ARGV;
open my $fh, '<', $fname or die $!;

my %cit_ids;
# Fill the hash with relevant ids
while (<$fh>) {
    while (m/<bib id="CIT-(?<name>\w+)-(?<id>b0*(?<num>\d+))">/g) {
        $cit_ids{$+{id}} = $+{name} . $+{num};
    }
}

seek $fh, 0, 0; # Rewind the file
while (<$fh>) {
    s/rid="(b0*\d+)"/rid="$cit_ids{$1}"/g;
    print;
}