Ok, I am going to skip the wildcard idea. I now understand that it can cause crazy bandwidth issue and DoS attack issues. Thanks for the feedback anyway.
But, can I route just one subdomain to the main domain foo.com?
(Sub)domain, Type, Target
foo.com, A xxx.xxx.xxx.xxx
"www.foo.com", CNAME, foo.com
How would this be done in the Dreamhost interface? Is it like this? Is there a period at the end? Can you help me with this?
[ , CNAME, foo.com. ]