While waiting for a reply I worked further on this and discovered the lines
vs.SetRField
vs.Reset
vs.GetRField
with the first I could successfully set the time. However, the rest of the object didn't update. So I had to write vs.Reset too, so the Heliodon updates according to the new Values.
However, even though I called GetRField after Reset, I still retrieved the values from before the Reset. Specifically I am talking about SolarAltitude. I set the time from 8:00 AM to 11:00 AM, reset the object and then retrieve the SolarAltitude. But it is still the same as at 8:00AM. When I then run this a second time, then I retrieve the 11:00 AM Altitude. In other words, the commands don't happen in the correct order.