When an Excel sheet containing a chart is copied to a new book, leaving it's
data behind, the chart retains the data values and data point values continue
to be displayed with the original formatting.

Unfortunately values in a data table loose their formatting, so what
appeared as 78% in the original data t able, now appears as 0.78956302

Is there a method of formatiing a data table without having to have the
original source data in the same workbook?

Excel 2003