EDIT: Oops, just realised you wanted it on a Graphical object and not for the buffers. I've never used EVENT objects, but I am assuming you can just set the anchor point at a future date like most other graphical objects.
ObjectCreate( ..., ..., OBJ_EVENT, ..., date_time_anchor, 0 )
Just apply a shift of the indicator's plotting along the time axis in bars. The Alligator indicator is a good example: