Point by coordinates node, reading the x, y, z from your excel file. Then you'll need to structure your lists to create the curves.
Can you at least give us a screen shot of your attempts so far?

This discussion could help you to get started but what you describe could be very hard to achieve if you did not learn the basics:
Topic: Piles position from excel (XYZ) | Dynamo BIM
You can refer to these sites for nodes and process descriptions:
Introduction | The Dynamo Primer
Dynamo Dictionary

Thats the problem, I need to make a script (if this is the right terminology) I have a few examples but they are more for inserting a specific family I really want to have these points define a model line and not (for example) the start and end point of a beam.

Heres the example I am trying, very basic for now.

In Civil 3D (or normal autocad would probably be ok too) I draw a hélix. Very simple, just use the hélix command and draw one with no special constraints.

I save or export this file (Have tried DXF, DWG - these I can not even import it just says the drawing is empty)
I actually have to export the civil 3D dwg to create a 3d model dwg and this inserts.

The main problem here is that I then go to either conceptual mass, or family editor (and I even tried in a blank project).
I insert the DWG and I can see my helix 3D line in the 3D view, but when I go to either draw a reference line, or a model line it does not allow me to pick the 3D line that is imported.

Same in the project file, I try to create an insitu component, and use "select path" and "pick 3D edges" as the pick line option to draw my sweep path and it will not let me select it.

So I see the only other way is to export the point data of the line, and have revit draw me a model line based on these points.

Is it posible to turn a dwg into model lines ?

I dont see why I cant get this to work, seems like it should do what i want but I simply can not see the dang 3D spline I am importing as a file.

It's there, I can see it in 3D view of revit, but dynamo cant find this object (and I cant use it to pick lines either)

The thing that is getting me here is its asking me to select a model element from "the document" What document?? The revit document, do I need to have this loaded in revit, then start the player in that project? That is what I am doing its not finding the linked file.

Am I supposed to preconfigure this file placement in dynamo? If so how do I do that?

I haven't worked with linked elements in Dynamo yet but I am aware there are nodes to select specific elements from linked files.
im guessing this is the start of your issue if your elements are linked and not imported. retrieving Revit geometry is different than say, reading geometry directly into Dynamo. I know Dynamo studio has direct import dwg nodes but not sure about Dynamo for Revit side of things.

The Select Model Element node has a Select button to clic on. Just clic on that and select the linked CAD file in your model. There are also other (custom) nodes that could be useful in your process later on: just download the excellent BimorphNodes package, for instance

Bimorphnodes package is excellent. However selecting linked cad file is not selecting specific polycurve inside linked cad file. How do we select a specific instance?