code: public String getRenderValueForCell(final FacesContext context, final String rowKey, final int col) {
  
          // if we have a submitted value still, use it
          // note: can't check for null, as null may be the submitted value
          final SheetRowColIndex index = new SheetRowColIndex(rowKey, col);
          if (submittedValues.containsKey(index)) {
              return submittedValues.get(index);
          }
  
          final Object value = getValueForCell(context, rowKey, col);
          if (value == null) {
              return null;
          }
  
          final SheetColumn column = getColumns().get(col);
          final Converter converter = ComponentUtils.getConverter(context, column);
          if (converter == null) {
              return value.toString();
          }
          else {
              return converter.getAsString(context, this, value);
          }
      }
docs: Gets the render string for the value the given cell. Applys the available converters to convert the value.
  
  @param context
  @param rowKey
  @param col
  @return