Change XML Variables on fly

Ok. I want to re-use this XML object, but replace some of the variables inside it.

Is there an easy way to do this?


   var c_bg_xml:XML = 
        <Motion duration="" xmlns="fl.motion.*" xmlns:geom="flash.geom.*" xmlns:filters="flash.filters.*">
         <source>
          <Source symbolName="c_bg">
           <dimensions>
            <geom:Rectangle left="0" top="0" width="1000" height="230.05"/>
           </dimensions>
           <transformationPoint>
            <geom:Point x="0" y="0"/>
           </transformationPoint>
          </Source>
         </source>
         <Keyframe index="0" y="240">
          <tweens>
           <SimpleEase ease="1"/>
          </tweens>
         </Keyframe>
         <Keyframe index="20" y="0"/>
        </Motion>;

Would like to change the widths, heights, index and so on … do I really need to parse the xml object, place in my own variables and then re assemble? Hmm …