Vendor/phpspreadsheet/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/Worksheet.php
public function insertNewColumnBefore($pBefore, $pNumCols = 1)
    {
        if (!is_numeric($pBefore)) {
            $objReferenceHelper = ReferenceHelper::getInstance();
            $objReferenceHelper->insertNewBefore($pBefore . '1', $pNumCols, 0, $this);
        } else {
            throw new Exception('Column references should not be numeric.');
        }

        return $this;
    }
public function insertNewColumnBefore($pBefore, $pNumCols = 1)
    {
        if (!is_numeric($pBefore)) {
            $objReferenceHelper = ReferenceHelper::getInstance();
            $objReferenceHelper->insertNewBefore($pBefore . '1', $pNumCols, 0, $this);
        } else {
            throw new Exception('Column references should not be numeric.');
        }

        return $this;
    }
Insert a new column, updating all possible related data.

@param int $pBefore Insert before this one, eg: 'A'
@param int $pNumCols Number of columns to insert

@throws Exception

@return Worksheet