Your best bet for using WebDAV from scripts on IIS would be to use
the WebClient class of ASP.Net. If you are using Windows XP or Windows
Server 2003, WebDAV functionality is part of the operating system. This
permits you to reference a file on a webserver using HTTP in the same
way you would use a UNC pathname. For example, you could map a drive
with NET USE * http://servername/directory and then access that
location using the drive letter. Alternatively, you can create a COM
object that is a WebDAV client. You can then use the object to issue
WebDAV verbs to IIS 5.x or IIS 6.0.

Additionally, if you search MSDN for WebDAV, you will find several examples of using XML to craft WebDAV queries for Exchange and other Microsoft servers.