Sorry, no. You can tell narrator which components of a window to read
(menus, message text, etc) but it is not possible to have it read a limited
portion of text within a single area.
There are keyboard shortcuts for narrator that can be used to skip some
items: Search for "narrator" in Windows Help and Support. Under "Overviews,
Articles and Tutorials" click on the link titled "Navigating with the
keyboard and Narrator."
You should be able to find more refined features, such as reading selected
text only, in a third party text-to-speech program.