Converting .NET SOAP call to PHP

I'm trying to create a script that pulls down an XML file that is created by a vendor using SOAP. Their only documentation is in VB.NET but I'm trying to use it in PHP - to no avail thus far. Below is the .NET example:

Private Sub GetData()
‘ Proxy is an arbitrary name I used to point to the City of Virginia Beach Web Reference URL.  
‘ You开发者_Python百科 may call it something else in your code.
        Dim soapHeader As Proxy.UserCredentials = New Proxy.UserCredentials
        soapHeader.Email = "YourEmailAddress@Domain.com"
        soapHeader.Password = "password"

        Dim ws As Proxy.Service = New Proxy.Service
        ws.UserCredentialsValue = soapHeader

        Dim forDate As DateTime = "1/1/2011"
        Dim result As String = ws.GetIncidentData(forDate)
    End Sub

Any help with this would be greatly appreciated.

I would start here: http://php.net/manual/en/book.soap.php
Curl can also be used for something like this: http://php.net/manual/en/book.curl.php