Add custom items in Breadcrumb NavXT

On my blog, I'm using Breadcrumb NavXT plugin. It works great.

On a specific portion of my site, I'd like to replace the normal breadcrumbs by custom ones. I have an array with the "parent" URLs, titles, and so on.

I don't understand how to "push" my informations into the plugin. My theme is only using this code :

if(function_exists('bcn_display')) {
    bcn_display();
}

My wish is to remove the normal breadcrumbs and add mine, like a "virtual nagivation path".

Any leads ? Thank you very much !

Edit: I want to add items to $breadcrumb_navxt->breadcrumb_trail->breadcrumbs , from outsite of the plugin's class. breadcrumb_trail is protected, so I'm looking for a way.