Azure CDN URL rewrite

Question

We are in the process of migrating CMS and would like to do this incrementally by page path, with all content residing under a common domain. In the target end state, we have Azure CDN fronting the website.

Given I have two origins during cutover, is there a way to resolve content from differing origins dependent on the request Uri?

We've tried setting up a redirect rule but that obviously exposes a different URL to the client. We've also tried a URL rewrite rule but unfortunately that doesn't allow us to change the host part of the url.