to_h

Returns Ruby Hash object which represents VT_RECORD variable. The keys of Hash object are member names of VT_RECORD OLE variable and the values of Hash object are values of VT_RECORD OLE variable.

If COM server in VB.NET ComServer project is the following:

Imports System.Runtime.InteropServices
Public Class ComClass
    Public Structure Book
        <MarshalAs(UnmanagedType.BStr)> _
        Public title As String
        Public cost As Integer
    End Structure
    Public Function getBook() As Book
        Dim book As New Book
        book.title = "The Ruby Book"
        book.cost = 20
        Return book
    End Function
End Class

then, the result of WIN32OLE_RECORD#to_h is the following:

require 'win32ole'
obj = WIN32OLE.new('ComServer.ComClass')
book = obj.getBook
book.to_h # => {"title"=>"The Ruby Book", "cost"=>20}