This isn't a Perl or Win32::OLE problem. What you need to do is look up the DOM for IIS in order to discover what methods are available from the IIS server object you are getting via my $obj=Win32::OLE->GetObject("IIS://$ip").

A quick google turned up this, and a quick browse suggests that you may be able to use something like

$obj->ConnectPath("IIS://LOCALHOST/W3SVC/");
[download]

to achieve your goal. You will need to find and read the DOM docs for your version of IIS.

Often, doing a Data::Dumper dump of the object handle returned by Win32::OLE will give some clues as to what properties, methods and collections are available at each level of object.

HTH.