s{ (\d+) : (\d\d) : (\d\d) , (\d+) }
 { $time = $1 * 3600E3 + $2 * 60E3 + ($3 + $dt) * 1E3 + $4;
   $h  = int $time / 3600E3; $time %= 3600E3;
   $m  = int $time /   60E3; $time %=   60E3;
   $s  = int $time /    1E3; $time %=    1E3;
   $ms = int $time;
   sprintf "%02d:%02d:%02d,%03d", $h, $m, $s, $ms;
 }gxe;