To copy selected fields from a QVD, create a QVW that loads only those fields and then saves the resulting table to the new QVD. If you need a subset of the rows, use a where clause when loading the source.
Its more complicated to copy selected information from a QVW - you can binary load the source QVD and then drop tables and or fields in the script. If you need a subset of the rows, use a resident load with a where clause and drop the original table.
Logic will get you from a to b. Imagination will take you everywhere. - A Einstein