If the machine you are on is part of the AD domain, it should have its name servers set to the AD name servers (or hopefully use a DNS server path that will eventually resolve your AD domains). Using your example of dc=domain,dc=com, if you look up domain.com in the AD name servers it will return a list of the IPs of each AD Controller. Example from my company (w/ the domain name changed, but otherwise it's a real example):
mokey 0 /home/jj33 > nslookup example.ad
Server: 172.16.2.10
Address: 172.16.2.10#53
Non-authoritative answer:
Name: example.ad
Address: 172.16.6.2
Name: example.ad
Address: 172.16.141.160
Name: example.ad
Address: 172.16.7.9
Name: example.ad
Address: 172.19.1.14
Name: example.ad
Address: 172.19.1.3
Name: example.ad
Address: 172.19.1.11
Name: example.ad
Address: 172.16.3.2
Note I'm actually making the query from a non-AD machine, but our unix name servers know to send queries for our AD domain (example.ad) over to the AD DNS servers.
I'm sure there's a super-slick windowsy way to do this, but I like using the DNS method when I need to find the LDAP servers from a non-windows server.