Changing retina.js retina image path

Question

When using images on a site, retina.js automatically looks for an image in the same folder with the same name with the added @2x, and then swaps out if the user has a high-DPI screen.

What I am trying to do is to tell retina.js to instead look for this retina @2x image in a sub folder. So if I'm using image.png, I want retina.js to look for [e-mail] in a subfolder named Retina for example.

I won't get into why I need this, but that is the gist of it. So then, is this possible, and where do I do this? I've found this part of retina.js that looks like it could do something along the lines of what I want, but I'm not sure how to proceed.

function RetinaImagePath(path, at_2x_path) {
    this.path = path || '';
    if (typeof at_2x_path !== 'undefined' && at_2x_path !== null) {
        this.at_2x_path = at_2x_path;
        this.perform_check = false;
    } else {
        if (undefined !== document.createElement) {
            var locationObject = document.createElement('a');
            locationObject.href = this.path;
            locationObject.pathname = locationObject.pathname.replace(regexMatch, suffixReplace);
            this.at_2x_path = locationObject.href;
        } else {
            var parts = this.path.split('?');
            parts[0] = parts[0].replace(regexMatch, suffixReplace);
            this.at_2x_path = parts.join('?');
        }
        this.perform_check = true;
    }
}

Thank you.