$array = array(
'@testvar@' => 'VAR1',
'@testvar2@' => 'var2',
'@info@' => 'This is some description',
'@url@' => 'url.lan'
);
$string = 'test#test2 = /@url@ test2#@testvar@.test2';
$escaped_keys = array_map('preg_quote', array_keys($array), array_fill(0, count($array), '/'))...