Help with DNS?

Okay, here's what I'm trying to do: I want to query a DNS server for the MX (Mail eXchange) records for a particular domain, but I haven't the slightest idea of how to do it! I'm experienced with the Winsock control, but:
--I don't know how to structure the query
--Once I've got the DNS server's address, I don't know what port to connect to

I could figure out how to interpret the results, but if someone has a canned solution (or even part of the solution) it'd be really appreciated!

Thanks in advance