Script for selecting all objects on a specific layer, do a pathfinder action and recolor everything

Hello everyone,

I need your help in creating a script.
The script should execute the following:

1. select everything and set the outlines to 0.5 pt and 100 K (CMYK).
2. select all objects from a specific layer.
3. pathfinder exclude
4. fill the selection with a specific colour field from the colour palette

Ideally, steps 2-4 can be used for several layers with different names and required colours. If a layer does not exist, the script should continue to run.

I have already been able to find the following commands, but always get a PARM error.

app.activeDocument.layers["Aluminium-Contour"].hasSelectedArtwork = true;
app.executeMenuCommand("Exclude");

Thank you very much!

Regards
Marc