private boolean setNumberValueIfAppropiate(Cell cell, String value, Styles styles) {
        BigDecimal bigDecimal = BigDecimalValidator.getInstance().validate(value, numberFormat);
        if (bigDecimal != null) {
            setBigDecimalValue(cell, value, bigDecimal, styles);
            return true;
        }
        else if (LangUtils.isNumeric(value)) {
            double number = Double.parseDouble(value);
            setNumberValue(cell, number, styles);
            return true;
        }
        return false;
    }
If value is an explicitly set value, then use that value to update the cell, otherwise if
ExcelOptions.isStronglyTypedCells = true then for cells check:
<pre>
Numeric - String that are all numbers make them a numeric cell
Currency - Convert to currency cell so math can be done in Excel
String - fallback to just a normal string cell
</pre>
Possible future enhancement of Date cells as well.

@param column the column from which value comes
@param cell the cell to operate on
@param value the ColumnValue value to put in the cell
primefaces/src/main/java/org/primefaces/util/ExcelStylesManager.java