custom url mycode

[1master1]

can we make it as addon my code? without changing the core [code] tag function in inc/class_praser, can we add additional custom mycode function below that existing [code] tag function?

function mycode_parse_code { --- }
additional custom function here   function mycode_parse_customcode { --- } with the same code functions but with that extra live links and non truncating feature without changing the main function mycode_parse_code { --- }