Please use OBJECT tag, add the codebase attribute in the tag.
If the object isn't signed, you should apply a certificate for it.
the component should support IPersistPropertyBag interface, if you write it in visual basic, you should save/read the property from PropertyBag, so that it can be initialized in PARAM tag.
If the ocx incldes other runtime, for example MFC or VBRUNTIME, you must add these dependence files in it,
please use OLEVIEWER to check the control support the property.