WinForms - Creating Virtual Directory Programmatically As Unprivileged User

I'm trying to write an application that will allow a non-administrator user to create virtual directories in IIS6. I've tried numerous different ways of impersonating a administrative account but nothing seems to work to create the virtual directory.

Here's some of what I've tried:
dim sDirPath as string = "IIS://remotehost/W3svc/1/root"
Dim de As DirectoryEntry = New DirectoryEntry()
de.Path = sDirPath
de.AuthenticationType = AuthenticationTypes.Secure
de.Username = tbxUsername.Text
[Code] .....

what is the correct way to impersonate another user in winforms application that will allow me to create the virtual directory without the user that's running the application being an administrator on the web server? I know this can be done, IIS manager allows you to use "connect as" checkbox to do it.