OK, how about this

#!/usr/bin/perl
use strict;
my (@certs,@lines);
@lines=<DATA>;
@certs = grep{/'([-.\w]+)'\s+added/,$_=$1}@lines;
#just to check
map{print"[$_]\n"}@certs;
__DATA__
Sep 12 17:30:02 nt-ca-na CA(Domain-CA): Certificate name 'jsmith.2048'
+ added to database.
Sep 12 20:09:37 nt-ca-na CA(Domain-CA): Certificate name 'ksmith.2048'
+ not added to database.
Sep 12 21:25:30 nt-ca-na CA(Domain-CA): Certificate name 'ssmith.2048'
+ added to database.
[download]

Hopes