copy data from resultSet to datawindow object
let r=new resultSet;
r.dataObject="c:\\temp\\myData.psr"; // Load PSR File with Data
r.copyTo(dw_1): // Copy to the current DataWindow
dw_1.item.itemcode[1]="test" // make changes
r.copyFrom(dw_1) //copy back to datastore
r.save("c:\\temp\\maData.psr"); // Save back
Note:
Field Nams and Types must be the same