(extracted from the web)
> WORKAROUND
> If you want to use PATH_INFO and PATH_TRANSLATED as specified by the CGI
> specification, then use the AllowPathInfoForScriptMappings property. This
> property can be set using the Adsutil.vbs tool or the MetaEdit.exe tool,
> which comes with the Internet Information Server 4.0 Resource Kit. Using
> this property, you can set a Web server to allow or disallow the use of
> the variables.
I've no idea about IIS, but it seems that using MetaEdit.exe or Adsutil.vbs you can configure IIS to accept that URLs.
Hope it helps