Creating parts from Spice models is pretty easy (but finding the menu items is a bit less so without reading the manual.)
Menu: Windows/Component Editor...
Then the easiest way is to click on the "Add Part Wizard" icon in the toolbar.
From your question, possibly you already knew that, and are wondering what format you need to use when asked for the model?
For a Spice model, select "Subckt", then select the Spice model file. Then it will ask for the subcircuit name, and for the symbol you want to associate it with, using the spice order for the pin numbering.
As to electrolytic caps, what exact problem would you like to simulate? I think you'd have to come up with your own model for this.