I have a bunch of Element and Node ID numbers listed in excel, I would like to know if I can bring them in Femap and locate/highlight them,... like copy/paste them in "Entity Selection Menu" in femap,...? Should it be done via Femap API?
No API is needed.
Copy them from Excel then use Window-Show Entities ( Node/Elem). The list can be pasted into the Entity Selection dialog box by using the "Pick" button then "Paste".