Is it possible to make "EmailEnabling" as required (*) while creating a security group by changing RCDC?

Hello,

I tried to change the "Group Creation" RCDC to make  "EmailEnabling" check box as required by putting  

<my:Property my:Name="Required" my:Value="true"/><my:Property my:Name="Checked" my:Value="true"/>

inside properties like the below

<my:Control my:Name="EmailEnabling" my:TypeName="UocCheckBox" my:Caption="%SYMBOL_EmailEnablingCaption_END%" my:Description="%SYMBOL_EmailEnablingDescription_END%" my:AutoPostback="true" my:RightsLevel="{Binding Source=rights, Path=Email}"><my:Properties><my:Property my:Name="Required" my:Value="true"/><my:Property my:Name="Checked" my:Value="true"/><my:Property my:Name="Text" my:Value="%SYMBOL_EmailEnablingValue_END%"/></my:Properties><my:Events><my:Event my:Name="CheckedChanged" my:Handler="OnChangeEmailEnabling"/></my:Events></my:Control>

but it is not at all reflecting in the group creation..

Please help me.