If i understand correctly, your setup is this:
you have one chunk, maybe called "News_Chunk", that contains the news (probably in html)
this chunk is used in every page
but your backendusers can't access this chunk for editing
If this is the way you want to do it, you could use a resource instead of that chunk:
create a resource called "News". Hide it from menues and unpublish it, so it does not appear anywhere else.
Then you enter the data, that usually goes into your chunk into the content-field of your resource.
Then, instead of calling your chunk like
you use a simple snippet like this:
create snippet "getNews"
$rid = $modx->getOption('rid', $scriptProperties, false);
if( !$rid ) return '';
if( !$r = $modx->getObject('modResource', $rid) ) return '';
return $r->content;
Call it like so:
where rid is the id of your News resource.
There are of course other, more flexible ways to integrate news, but if this works for you that's fine.
