Here again a little math is required. Notice the two clues on the screen: B=7 and M=18.
If you count the number of B in the alphabet, it comes to 2 and M comes to 13. This means that 5 has been added to both alphabets.
So the message on the screen says that you require TNT. T=20 and N=14 in the alphabet. Add 5 to both and the numbers form like so: T=20+5=25,N=14+5=19 and T=20+5.
TNT will form 25,19 and 25. Press the keypad and input the numbers 251925 and press OK. This will unlock the bars and you can proceed to the next level.