I have the following Excel file:

I read it in by looping
If you are unsure about the content of a cell (value or formula included), I recommend you to primarily do a check if the cell has a formula and then copy - paste accordingly. getOldCalculatedValue() is very helpful in this case. Here is an example of that:
$code = $sheet->getCell('A'.$y)->getValue();
if(strstr($code,'=')==true)
{
$code = $sheet->getCell('A'.$y)->getOldCalculatedValue();
}
$objPHPExcel4->setActiveSheetIndex(0)
->setCellValue('A'.$l, $code);
For large data sets, getCalculatedValue() function is really cumbersome and lots of memory will be required to perform correctly.