Using ActiveX in CVI 6.0 is very simple!
Select Tools»Create ActiveX Controllor pick the server you want to use and step through the rest of the wizard.
When you are done CVI will have created a .fp file which you can add to the project from Instrument»Load. In the instrument menu you will then see an entry for your ActiveX server which will expose all of the methods, give you get and set functions for each property, and allow you to install callbacks for all ActiveX events.
More information is abound in the Devzone Tutorials section of this site and other places you can search in this site.
Best of Luck!
Amaury R.
Applications Engineer