<zk>
    <grid width="600px">
<!--        <custom-attributes org.zkoss.zul.css.flex="false"/>-->
        <columns menupopup="auto">
            <column label="Col-1" width="100px" visible="false"/>
            <column label="Col-2" hflex="1"/>
            <column label="Col-3" hflex="1"/>
            <column label="Col-4" hflex="1"/>
            <column label="Col-5" width="100px"/>
        </columns>
        <rows>
            <row>
                <label value="cell-1"/>
                <label value="cell-2"/>
                <label value="cell-3"/>
                <label value="cell-4"/>
                <label value="cell-5"/>
            </row>
        </rows>
    </grid>
</zk>