Using Codeigniter in a Wordpress plugin

[admin]

This might seem a bit of a weird question but I have some CI code I'd like to include as a WP-plugin.

When doing this, how would you access a controller function as a shortcode, for example:

myurl.com/controller1/method1

would map to controller.php

function method1(){
}

Assuming the CI is in the content/plugins folder as an installed plugin, how would I map myurl.com/controller1/method1 to a WP shortcode such as <b>[controller1-method1]</b>

Or would it be simpler to re-write as a wordpress plugin?

Thanks