If i have a word like c.........a......t (with the dots in) and i wanted to replace it with cat how would i do it. If i use

CODE

<?php
$patterns = "/c(*)a(*)t/";
$replace = "cat";
echo preg_replace($patterns, $replace, 'c.....a.........t');
[/color][color="#000000"]?>

then when i type something like "come and look at this" is also filtered. Is there any way just to filter cat with dots in?

If all you want to do is eliminate dots found specifically inbetween the letters "c", "a" and "t", then the following should work:
Anything else would require a more complex pattern.