string - php How to add comma's in an array without making it separate values? -

my string:

'kcp-pro;first_name last_name;address;zipcode;country' //for example: 'kcp-pro;jon doe;box 564;02201;usa' or 'kcp-sat-pro;first_name last_name;address;zipcode;country' 

how can change first part (kcp-pro or kcp-sat-pro) , change (kcp,pro or kcp,sat,pro)? outcome has be:

'kcp,pro;first_name last_name;address;zipcode;country' or 'kcp,sat,pro;first_name last_name;address;zipcode;country' 

i haven't tried code myself guess trick

$string = 'kcp-sat-pro;first_name last_name;address;zipcode;country';  $stringexploded = explode(';', $string); $stringexploded[0] = str_replace('-', ',', $stringexploded[0]); $output = implode(';', $stringexploded);  //output should kcp,sat,pro;first_name last_name;address;zipcode;country 

hope helps :)