I can't tell you how to make a custom renderer... it's been on NotesIn9 a couple times I think.  But if you want to alter it I think that's you're only option.

good Luck!

Patrick, on Github you can have the original code of the pager Add Rows

https://github.com/OpenNTF/XPagesExtensionLibrary/blob/master/extlib/lwp/product/runtime/eclipse/plugins/com.ibm.xsp.extlib.controls/src/com/ibm/xsp/extlib/renderkit/html_extended/data/PagerAddRowsRenderer.java

You can copy it to your own database as Java class, make a reference to it in the Faces-config.xm, see http://www.pipalia.co.uk/xpages-2/creating-custom-renderers-for-xpages-controls/

In this example the renderer is added to the component, but you can also specify the renderer also in your Theme, like I did for my own pager renderer

<name>Pager</name>

        <property>

          <name>rendererType</name>

          <value>nl.elstarit.renderers.type.BootstrapPagerRenderer</value>

        </property>

      </control>

And alter your renderer to your needs.