The OpenSpan team has released their Windows application container for Lotus Notes 8.5 and Lotus Expeditor 6.2. It's not just VB apps though, it is any Windows based application that can be used within a composite application.
OpenSpan recently announced the OpenSpan Windows Container for IBM Lotus at IBM's 2009 Lotusphere Conference. This new offering enables and extends IBM Lotus Notes (version 8.5+) or IBM Lotus Expeditor (version 6.2+) to integrate and automate applications not currently supported by Expeditor, including native Windows desktop applications.
They also have a pretty slick video that shows the basic concepts.