Hi,
If you want to copy the cells from one Spread to another like that, you should use GetClipDataObject:
Using that method, you can specify a range of cells, columns, or rows (use -1 for Column/ColumnCount for rows and -1 for Row/RowCount for columns) and get all formatting/values/formulas/etc. using ClipboardCopyOptions.All, with just one line of code. Then you can paste that data into another Spread using one more line of code:
Hope that helps!
Regards.
-Sean