I am not quite sure if this is what you're looking for, but in my projects I use a COM interface, once you've registered it, you can use it like this:
$myObject = new COM("MyCOM.MyObject");
$myObject->WhatEverFunction($var1, $var2,...);
The above is equivalent to the follwoing VB ASP code:
set myObject = CreateObject("MyCOM.MyObject")
myObject.WhatEverFunction($var1, $var2,...)
The registration on your windows system is the essential part.
Hope this helps...
T