Updating Text In A MovieClip

I am trying to create a text box which I can dynamically update from an XML file and move around in 3D at the same time. Is it possible?

I can create a dynamic text field and update if from an XML file and…
I can create a dynamic text field, convert it into a Movie clip allowing me to move it round the screen but I can’t do both without losing the text (I have also tried embedding the font).

Is it fundamentally possible in CS4 or CS3 to dynamically update a text field once it has been converted to a MovieClip/Symbol?

I found this tutorial the other night but I don’t think it would work with an xml file being regularly updated: