Clone the dataset and modify the data on the clone.
A document on it by Cary Jensen is here: http://edn.embarcadero.com/article/29416
Basically you need something like
var
lEdDataset: TClientdataset;
begin
lEdDataset := TClientDataSet.create(nil);
try
lEdDataset.CloneCursor(SourceDataSet, True**);
StoreMedDeviceRecord(lEdDataset);
finally
lEdDataset.free;
end;
** You'll need to read the documentation on the True/False settings and decide what you actually need (I can't remember off-hand)