Assignments among OLEControl, OLECustomControl, and OLEObject datatypes – PB Docs 2021

You cannot assign an OLE control (object type OLEControl) or
ActiveX control (object type OLECustomControl) to an OLEObject.

If the vendor of the control exposes a programmatic identifier (in
the form vendor.application), you can specify this identifier in the
ConnectToNewObject function to connect to the programmable interface
without the visual control. For an ActiveX control with events, this
technique makes the events unavailable. ActiveX controls are not meant
to be used this way and would not be useful in most cases.

You can assign the Object property of an OLE control to an
OLEObject variable or use it as an OLEObject in a function.

For example, if you have an OLEControl ole_1 and an
OLECustomControl ole_2 in a window and you have declared this
variable:

then you can make these assignments:

You cannot assign an OLEObject to the Object property of an OLE
control because it is read-only. You cannot make this assignment:

Events for OLEObjects

You can implement events for an OLEObject by creating a user
object that is a descendant of OLEObject. The
SetAutomationPointer PowerScript function assigns an OLE automation
pointer to the descendant so that it can use OLE automation.

Suppose oleobjectchild is a descendant of OLEObject that
implements events such as the ExternalException and Error events. The
following code creates an OLEObject and an instance of oleobjectchild,
which is a user object that is a descendant of OLEObject, connects to
Excel, then assigns the automation pointer to the oleobjectchild:

You can now use olechild for automation.