I hate to break this to you, but the Christian god is not conceived of as external to nature, given that he created it. Neither is Plato's, of which nature is a dim reflection.
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I don't know where you got this from Chris but it's a direct contradiction of just about everything I was taught growing up in a Christian environment (home, school and of course, church).
As John Thornton mentioned, practicing Christians describe God as omniscient and omnipotent, as the 'author and finisher'. Paradoxically woven into the structure of 'nature' (in the creator role, speaking existence into existence -- "And God said, "Let there be light"; and there was light..." Gen 1) and yet, able to observe it from the outside as a created thing.
The ultimate expression of the word, 'SUPERnatural'.
I'm sure this is an old idea but it's very useful for modern Christians who reconcile a universe of discoverable, 'natural laws' with belief in a god who can dismiss those laws at will (Red Sea partings, manna dispensing clouds hovering over wandering Israelites, immaculate conceptions, etc).
Who or what told you that god was "not conceived as external to nature"?
.d.