How to save a Registry Key

Hello all!
I have been trying to play with the registry some. Mainly, I have the following problem:
I would like to save a registry key (and all subkeys, etc. associated with it, just like you would when doing it with regedit), and then import it.
The problem here is that I cant really use .reg files since the user running the app wont have permissions to use regedit. I've been trying to use RegSaveKey and RegRestoreKey, but RegRestoreKey just overwrites the whole thing, unlike a .reg file which does deltas.
Anyone out there can help me on how to do this? Parsing through every little value, reading and writing, would be a nightmare. I want something that can take it all (say, under HKEY_LOCAL_MACHINE/Software/Office) and then be able to dump all that info into the registry again at a future point.