Returns a Document by its index or its name from the linked Documents
collection.
Parameters:
iIndex
The index or the name of the linked Document to retrieve from
the collection of linked Documents.
As a numerics, this index is the rank of the linked Document
in the collection.
The index of the first linked Document in the collection is 1, and
the index of the last linked Document is Count.
As a string, it is the name you assigned to the collection by using
the