Well, I've already experienced the problem of the quotes, I'll do my best getting it works, thanks again Mr kh99.
--------------- Added [DATE]1324417995[/DATE] at [TIME]1324417995[/TIME] ---------------
Wow, unbelievable, it worked

.
I've never imagined I can experience something complicated like that, anyway, take a look at the code (however it is

) because I have a little issue:
PHP Code:
$find = '<span class="date">';
$replace = '<span class="date">\';if($post[\'isfirstshown\']) { $final_rendered .=\'hh\'.$fetch[\'data\'].\'gg\'; } $final_rendered .=\'';
Now it shows "hhgg" just in the first post, but not $fetch[\'data\'], what the problem?
I'm glad that the big problem is solved.