php - Highlight substring which can contain own extrac characters -

i need create function, highlights searched substring. example, have string "123456789" , search substring "234". it's easy, need create function:

str_replace('234', '123456789', '<b>234</b>'); 

but string can contains 4 (only four) special characters (" ", "(", ")", "-") need jump over.

so can have string "12 3(456)78-9)" , still need highlight searched "234", final string needs like

"1<b>2 3(4</b>56)78-9)" 

do have suggestions how this?

edit: string , substring can contains character, not numbers example string: "poly(amide 610)" , searched word can "polyamide6" - highlighted "poly(amide 6"

you need put subpattern describe characters want skip between each character of target string:

$str = '12 3(456)78-9)'; $needle = '234'; $neutral = '[ ()-]*';  $pattern = '/' . implode($neutral, array_map(preg_quote, str_split($needle))) . '/iu';  $result = preg_replace($pattern, '<b>$0</b>', $str);