[libvirt] Reusing dumpxml output

I would like to reuse configurations that have been edited using the libvirt api. For example by attaching interfaces. Now the output that dumpxml generates, is very 'specific' to an active configuration. I am not able to use a stored configuration from an active domain to redefine it after it has been undefined. Is there a trick to do so? Or should one really strip all 'live' attributes first? Stefan