Page Number for each chapter in master page

[marco.nap83]

Hi to all, I was looking for a solution about a problem on I'm thinking about it since few days. I try to explain it in the easier way. I have a master report where I collect a lot of details. Each detail contains a paragraph consisting in a paragraph title and a sub report that it can linked to more than one report (because I could scan more nested list). In main report I have a details that contains an index. The index is composed by text label. Near each text label I would put the page number linked to each paragraph, let's call it A. I understood that this number should be represented by a variable that should be tide to a variable, in a subreport, that store the paragraph page number. Let's say that I can try it out in the report page that contains the second chapter. Inside the second chapter report page if I use the default variable $V{MASTER_CURRENT_PAGE}, with evaluation time master, I can read the right number page, let's say number 5. Now the problem is take this number and send back to A(it doesn't matter how many sub report I have between the chapter page and the the master page). I read some documentation and I understood that to do it I should declare in master page the A variable, click on the band that store it and go to return values and tide A with the name of  each chapter  $V{MASTER_CURRENT_PAGE}. How can I do it? I tried to do different test, for example to declare a new variable in each chapter page, let's say B, and link B to $V{MASTER_CURRENT_PAGE}, and after link A to B. In this case in the master page I got every time null (I tried to change all evaluation time possible but I don't understand how to do it so far).

In the first case works just in the chapter page but I don't know how to send back to master page this value:

    <textField evaluationTime="Master">
                <reportElement x="170" y="0" width="240" height="30" uuid="0bc4318d-5b1b-4add-bcc7-422bc299096a"/>
                <textFieldExpression><![CDATA[$V{MASTER_CURRENT_PAGE}]]></textFieldExpression>
     </textField>

In the second case I declare in the chapter page and I try to tide it to variable A but also in chapter page the current page appears null. In chapter page:

<parameter name="custom_page" class="java.lang.Integer">
        <defaultValueExpression><![CDATA[$V{MASTER_CURRENT_PAGE}]]></defaultValueExpression>
    </parameter>

Thanks to all.