<h:form>
<h:panelGrid binding="#{myBean.myGrid}"></h:panelGrid>
<h:commandButton id="submit" type="submit">
</h:form>

public HtmlPanelGrid getMyGrid()
{
  resultGrid = new HtmlPanelGrid();
  resultGrid.setColumns(2)
  List children = resultGrid.getChildren();

  FacesContext myFacesInstance = FacesContext.getCurrentInstance();
  Application myApp = myFacesInstance.getApplication();
  ExpressionFactory expFactory = myApp.getExpressionFactory();

  SelectItem tempSelectItem;
  String valuStringExpression;
  ValueExpression valExpression;

  //create panel for the checkboxes
  HtmlSelectManyCheckbox checkboxPanel = new HtmlSelectManyCheckbox();
  checkboxPanel.setLayout("pageDirection");

   List<SelectItem> checkChoiceList = new ArrayList<SelectItem>();

   for (int i=0;i<numChoices;i++)
   {
    valStringExpression = "#{myBean.responseValue["+i+"]}";
valExpression = expFactory.createValueExpression(myFacesInstance.getELContext(), valStringExpression, String.class);
    tempSelectItem = new SelectItem(valExpression,choiceLabels.get(i));
    checkChoiceList.add(tempSelectItem);
   }

  UISelectItems checkboxList = new UISelectItems();
  checkboxList.setValue(checkChoiceList);
  checkboxPanel.getChildren().add(checkboxList);

  children.add(checkboxPanel);

return resultGrid;
}

value="ValueExpression[#{myBean.responseValue[0]}]"

Object value = valExpression.getValue(elContext);
tempSelectItem = new SelectItem(value, choiceLabels.get(i));