Autoblog and "manual" posts

I am using autoblog to post excerpts with links from several blogs/sites and to generate a single feed (on my site) for some mailchimp RSS campaigns. So far, so good.

But there are some sites I would like to post excerpts and feature them on my website feed and mailchimp RSS campaigns with links to them, but they don't have feeds. My first thought was that I could publish a post on my website but use the same custom fields from autoblog (e.g. original_guid, original_feed, etc) and they would appear on my feed pointing to external source, but this won't work.

Is there any way, any method to create my on "manual" posts pointing to these sites with no feeds?