Typo3: display content from first sub-page using typoscript - typo3

Question

This is what I want to do: on a given page, I want to display all content elements of the first child page of a given page. I cannot simply use a shortcut page, because I need to display other content elements after the ones from the sub-page. How can I do this?
Here is a snippet of how I think I could do it, but I don't know how to build the select. Is there a better way?
# save current content
tmp.pagecontent < page.10.subparts.main-content
# clear the content of the main column
page.10.subparts.main-content >
# build a new object for this column as content-object-array
page.10.subparts.main-content = COA
page.10.subparts.main-content {
10 = CONTENT
10.table = tt_content
10.select {
# what should I put here?
}
# re-insert the normal pagecontent to the page
20 < tmp.pagecontent

Answer 1

Just add answer for other people.
First : specify the first sub page of current page.
Second : get content elements that you want of that sub page.
temp.content = COA
temp.content {
10 = CONTENT
10 {
table = pages
select {
pidInList.field = uid
orderBy = sorting ASC
max = 1
begin = 0
}
renderObj = COA
renderObj {
10 = CONTENT
10 {
table = tt_content
select {
languageField = sys_language_uid
pidInList.field = uid
orderBy = sorting
#where = colPos = 10
}
stdWrap.wrap = |
}
}
}
}

Answer 2

I finally succeed! Not sure though it is the best way. What do you think about it? Should I put the second select into userFunc too?
fileadmin/userfunc/mailArchive.php
<?php
class user_mailArchive {
function getFirstChild($content, $conf) {
$res = $GLOBALS['TYPO3_DB']->exec_SELECTquery(
'uid', // SELECT ...
'pages', // FROM ...
'pid='.intval($conf['pid']), // WHERE...
'', // GROUP BY...
'sorting', // ORDER BY...
'1' // LIMIT ...
);
$row = $GLOBALS['TYPO3_DB']->sql_fetch_assoc($res);
if ($row) {
return $row['uid'];
}
else {
return '';
}
}
}
TS template
# fill the content of the main-column to a tmp.object
tmp.pagecontent < page.10.subparts.main-content
# clear the content of the main column
page.10.subparts.main-content >
includeLibs.mailArchive= fileadmin/userfunc/mailArchive.php
# build a new object for this column as content-object-array
page.10.subparts.main-content = COA
page.10.subparts.main-content {
10 = CONTENT
10 {
table = tt_content
select {
pidInList.cObject = USER
pidInList.cObject {
userFunc = user_mailArchive->getFirstChild
# parent page ID
pid = 139
}
orderBy = sorting
}
}
# re-insert the normal pagecontent to the page
20 < tmp.pagecontent
}