How do I add time limit in Control Box from Alien vs, Predator by SERGEUS

[Riku Minato]

Hi Guys............I recently playing in mugen I now in bonus stage my characters are try to finish to destroy the Control Box with a time of 20 sec.but suddenly its already over its not fun for me..........And also I try to find the code this character to additional time limit but I can't find it, Anyways heres the image: 

Is anyone know how to add the time limit?