Although I've already replied back at cgtalk, the comment here turns it into a slightly different topic. In a situation like this, the only way I can think of to get the new copy of $Plane000 (assuming this default prefix as you are not specifying any other) by name would be searching for n of the $Plane* nodes with the highest number - don't do that, ever.
It doesn't matter that in this particular case, there's a simple solution where you get the node returned directly; in some cases (such as the detach command) you won't. Again, the detached object would get the default Object prefix, but actually the easiest way to get it is just
obj = objects[objects.count]
Same applies for a bunch of newly created objects: get a count of objects before, then when yu get some new nodes in the scene through a process over which you have little or no control (think third party plugins), simply collecting the nodes starting from the previous count raised by one will get you there.