How to do a deep copy of one dataset to another.

I have a very large dataset and want to copy several rows to another dataset with an actual deep copy. I don't want the new dataset rows just to be another reference to the same data in memory as the original dataset but rather for it to be a separate dataset with an actual copy of the data (or a subset of rows of the original data).

How do you copy the contents or a subset of the contents of a dataset to another. I want to be able to use this other dataset to bind to a separate datagrid than the original one