For those who come across this forum topic later with the same question...
You can see examples of how to do Win32Ole / COM in the demo QuickBooks rubygem, available at quickbooks | RubyGems.org | your community gem host.
The full version is available for sale at http://behindlogic.com, but if all you want is the COM communication, you can get that out of the demo gem.
Also available at http://behindlogic.com is an HTTP Connector that makes it possible to use the gem (or other quickbooks-integration project in any language) from a different computer.
