These are generic articles on ActiveX: -
From the Activex perspective they will put you on the right track.
ActiveX and LabVIEW
http://zone.ni.com/devzone/cda/tut/p/id/2983
Using ActiveX with LabVIEWhttp://zone.ni.com/reference/en-XX/help/371361B-01/lvconcepts/using_activex_with_labview/
Calling an ActiveX Object from LabVIEW
http://zone.ni.com/reference/en-XX/help/371361B-01/lvhowto/calling_an_activex_object/
ActiveX/COM Overview
http://zone.ni.com/devzone/cda/tut/p/id/3831
Why Can't I Select an ActiveX Object from a Library?
http://digital.ni.com/public.nsf/allkb/9238D0C181AC396D86257267005AB3E4