You question is not that clear..but still based ona guess like
if you want to insert some values into an array based ona sequesnce from a conf file you have to check the order in the conf file first and the use array_push() function to insert the value.
I don't have a ready example to show you, but what you'll need to do is read in the file, Use the Explode Function to convert the text to an array.
$array = explode("\n", $string); arguments are 'delimiter' and 'string to explode'
use array_push to add variables to the array.
use the implode function to rejoin the array.
write the array back to the file.