Add XAML into existing richtextboxeditor

Hi,

I have a richtextboxeditor that has imported and loaded an XAML document. I have another XAML document/section I would like to append/merge with the existing one. Using import method only erase prior loaded XAML and not append the new XAML content. Haven't been able to figure out a way to add XAML / append it to the already loaded XAML document. Any help would be appreciated.

J