EDIT DATA ROWS IN COPIED CHART

I have created a new register and copied all data including a chart.
I can edit the data references in the new register to point to the new register, but I cannot edit the sources of the data rows in the copied chart.
Do I have to create a new chart and all the data rows and references or can I edit the new chart??

Further explanation:
The original register contain accounting data and a chart for a calendar year.
I have copied the contents to a new register, and have edited the new data references to point to the new register.
The data rows in new chart still point to original register and cannot be edited!!