Win32::OLE is an API to access OLE/COM Servers. Word is an OLE Server and it has an Object Model defined in it's documents or in the macro suite as mentioned in
Re: Where is the Win32::OLE Docs. The properties/methods and the types of arguments to pass to them are defined in the Object Model. Grab a copy of
Win32 Perl Programming: The Standard Extensions (2nd Edition) for a gentle introduction to OLE Automation. It's old but still valid. It will not help you to write MSWord controllers but will help you to understand how it works and summarizes the core concepts.