If I understand your question correctly, to integrate new data without losing old data, in your script you would need to first load the old data into a temp table, concatenate the new data into the temp table, then export the temp table back into your QVD (I'm assuming that's what you're using), which will be overwritten with all the data combined.
Oh, I see what you mean. No, that's not how QlikView works. QlikView clients are always read-only so the user can't add anything. The only exception to this is "Allow dynamic data update" under Server Settings. This will enable the functionality you are talking about, but you need a special QVS license that includes the DYNAMIC_UPDATE:YES tag.