SimpleRSS how do you read dc:date attribute

I used simpleRSS to parse my rss and I need to read
feedburner:origLink tag. But simpleRSS doesn't have that. I added this
to @@item_tags in the source code. But once I read the feed, the RSS
content that is returned doesn't have this.

What can I do, to read origLink tag.

Thank you.