The Microsoft DNS server doesn't have this capability. I'd echo what @MDMarra says in his comment-- tell us what you're really trying to do.
You could use BIND's "views" functionality to do this, but that would be a bit of a hack (to me).
Windows clients contain code to determine their site and locate domain controllers based on their site. In particular, Group Policy processing is "site aware" and group policy objects can be linked to sites. Anticipating your needs a bit, perhaps, you could use a GPO linked to a site to set environment variables on clients, allowing programs running on the client to become "site aware" without having to re-implement the algorithm Windows to determine the client's site.