Wordpress-like Shortcodes using CI

[eluser]Mantero[/eluser]
how do we create a shortcodes using CI?

I want to make something like this:

[list type=plus]
-list 1
-list 2
-list 3
[/list]

so the view will display a list with a 'plus sign' as a bullet(yeah the plus sign will be use css for sure)

but if use shortcode like this:

[list type=yes]
-list 1
-list 2
-list 3
[/list]

this will display a list with 'yes/right' sign..

anyone know how to do this?

this implementation just like a wordpress shortcode