Query builder - like() with wildcard within a string

Hi,

I know I can use wildcards on the beginning and end of the string, but I can't figure out how (or if) I can use it withing the string.

I know how $this->db->like() works:

PHP Code:

$this->db->like('title', 'match');  //produces WHERE `title`LIKE '%match%' 


but sometimes I need to match just one charachter with "_" withing the match string or something more custom

PHP Code:

WHERE `title` LIKE 'ma_ch'
WHERE `title` LIKE 'ma%h%' 


Thanks