ActionScript 3.0 :: Embed Stylesheet And Load It On Demand

I'm trying to implement way so that stylesheets can be loaded on demand: Either the default stylesheet is used, which is compiled into the application file, or a remote stylesheet (.swf) is loaded if the default styles should not be used. (each stylesheet has embedded images)

So what I would like to do is:
1) Embed the stylesheet but not load it right away. Instead, store a reference to it inside a variable. (or simply a path string?)
2) Load the requested stylesheet, for example using StyleManager

My way of tackling the problem was like this:
1) Embed the default stylesheet as
Code:
[Embed(source="assets/themes/default.theme.swf")]
_defaultThemeClass:Class;
and turn it into a StyleSheet object

2) Have a separate class decide which stylesheet to use and call StyleManager.loadStyleDeclaration(myStyle), where myStyle can either be the remote or local stylesheet.
As it seems, the StyleManager cannot load a local stylesheet. So I'm looking for a way to "activate" the style I have embedded.