Not in Flash - but if it's embedded in an HTML page, you can overlay a div on top of SWF and manage its contents with JS / ExternalInterface. For all goals and objectives, the effect is the same, you just need to think about updating its information about where it should be and what it should contain.
TextFields have an html rendering option, but I'm not sure how many tags are supported, it never worked for anything that I tried, and I can not find any links to it on the Internet.
EDIT. HTML SWF, "wmode" "direct" ( Stage3D) - SWF , . , .