example showing a copy/paste of a subset of a first file to a subset of a second one.

Hello all
I am new at this mailing list (and new at hdf5 java Object API).
I am looking for an example of code showing how to extract a subset out of a first hdf5 file, and next write it in a subset of another file.
Sorry if this has been already discussed but I found it difficult to search the mailing archive.
Thank you in advance.