Spline Mesh Generation: Hopw to change Mesh at specific key

Hello Forums!

I have a simple setup of a procedural built wall, using a spline. This works very well for a single mesh. I also implemented to change the start and end mesh. Now what I need to do is to change the mesh at a specific key.

For example:

I created a spline with n=5 vertices. A simple wall mesh is applied along the spline.
If I’d like to change the first and/or the last mesh, I can easily find the corresponding vertices via math.
In the next step, I want to change the mesh at vertex n=3 to a different mesh. How would I do that in a blueprint?

I think I am very close to the solution, but can’t figure it out right now…

Please help!