Vista - parsing templates

Hi,

I'd like to do the following: I have a representation of a datatemplate
visual tree as xaml. I would like to dynamically load the xaml, parse it and
apply it to an existing data tempate object that resides in the resources of
my existing page.

At the moment I have no clue how to do it. Somehow I have to get a
FrameworkElementFactory object from the xaml description.

Thanks,
Falk