JExcel: Copy a cell content from one sheet to another sheet in the same workbook.

Hi.

Please provide code for the following topic.
How i can copy a cell content from one sheet to another sheet in the same workbook,

Already i created a workbook as a copy of existing workbook, but i am not able to copy cell value of sheet 1 to sheet 2, 3, 4.....

I used the follwing code to indicate the sheet
Sheet sheet = workbook.getSheet(1);

but there the following code does not work.

sheet.addCell(new Label(4, 1, "STring 1",times12formet));

The above code can be currect while creating a new sheet. so is there any code that a cell value to be copied from one sheet to another.

Thanks in advance.
Uttam