The [GenericVST] object that's part of my Live Keyboard Rig Manager library can do this easily.
For example, the patch below demonstrates this (it's all you need if you put my library in your search path).
This patch instantiates a Reaktor VST and tries to load the settings called foo. Those settings obviously won't exist the first time around.
Double-click on the GenericVST object to open it in presentation mode. There you will find a button called Edit. Click that to open the Reaktor GUI. Then just load in whatever ensemble you want, change the parameters as desired.
Finally, click the "Save settings" button in that presentation mode object to save the current parameters to "foo".