How to connect existing beams to sloped roof, so as the slope of the roof changes the beams angle changes accordingly?

I am learning to use Dynamo and attempting to use nodes to link existing beams to a sloped roof.
I have an existing structural framing beams and a sloped roof. I want the edge of steel to sit at the bottom of the sloped roof.
Additionally the slope of the roof may change, as the architect sees fit. So I would like the angle of the beams to adjust as the slope of the roof changes.

I am new to Dynamo so I would prefer to do this with nodes, rather than direct coding. Can you give me any tips? I’m stuck.

My Attempt:
(I tried assigning the beams to a reference plane that sits on the bottom face of the roof, but it isn’t working)

  • Parameter.ParameterByName of selected beams = “Work Plane”
  • Element.GetParameterVauleByName of selected Reference Plane = “ROOF ReferencePlane”
  • Use Parameter.SetValue and assign Parameter.ParameterByName to parameter and Element.GetParameterValueByName to value
    (My thinking is that there is an Parameter of the Beams, “Work Plane”, and I need it to equal the Name of the selected Reference Plane, “ROOF ReferencePlane.”)

Am I way off track?

You can project the beam to bottom of the roof surface