checkbox.vb

'VBA
'Checkbox
Sub chkBox_onAction(control As IRibbonControl, isPressed As Boolean)
    'Display status of checkbox in cell: TRUE or FALSE
    Sheet1.Range("H9").Value = isPressed
End Sub

checkbox.xml

<!--XML-->
<!--Checkbox-->                          
    <group id="grp_chkBox" label="Checkbox">               
        <labelControl id="lblCtrl_dummy1" />           
        <checkBox id="chkBox" label="View 1" onAction="chkBox_onAction"/>  
    </group>