LabVIEW is very easy to use with ActiveX. Click on NI Developer Zone -> Development Library -> LabVIEW (under Measurement & Automation Hardware) -> Communicating with External Applications (under Development System) -> ActiveX. There are lots of examples and papers that you can use to help you get started.
Basically, you just place an ActiveX container on your LabVIEW front panel and then use property nodes and invoke nodes to communicate with your ActiveX control. This
tutorial is also a great place to get started.