private void updateCellStringValue(Cell cell, String value, Styles styles) {
        boolean printed = false;
        if (stronglyTypedCells) {
            printed = setNumberValueIfAppropiate(cell, value, styles);

            if (!printed) {
                printed = setCurrencyValueIfAppropiate(cell, value, styles);
            }
        }

        // fall back to just printing the string value
        if (!printed) {
            cell.setCellStyle(styles.getDefaultStyle());
            cell.setCellValue(createRichTextString(value));
        }
    }
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