exportable with render is not workin

Here i am using check box for my table's column to show or hide.

<p:column colspan="1">
<h:outputText value="Dirver Name" style="margin-right: 15px"/>
</p:column>
 <p:column>
<p:selectBooleanCheckbox value="#{selectedColumnsBeanForDPR.driverName}">
     <!--<p:ajax update="tbl" />-->
                                                        </p:selectBooleanCheckbox>   
    </p:column>

in my data table is perfectly working, but problem is that here i am also using exportable with same value like:

 <p:column headerText="Driver Name" rendered="#{selectedColumnsBeanForDPR.driverName}" exportable="#{selectedColumnsBeanForDPR.driverName}">
                                            <h:outputText value="#{car.customer.firstName} #{car.customer.middleName} #{car.customer.lastName} " />

                                        </p:column>

exportable is not working in this case although render is working with the same value. I donnot understand why this happening. When i am simply putting exportable="false" it is working fine. But I want to use my check box variable to perform thi.. any solution here?