See if this link gets you moving. I have done exactly what your after,. It I don’t have access to the graph at the moment…the main thing is you need to get an element already in the schedule, then copy it and change data.
But my point is more that i see a lot of topics about exporting and importing to or from Excel.
Often i feel this add-in does a better job than Dynamo (for this task) or this add-in is suited for posters needs.
Personally i only turn to Dynamo for exporting and importing to or from Excel when this add-in really can’t do what i am after.