You can do this cheat as many times as you need.
1) Go to Data Sheet
2) If directing direction pad on your controller to up is N and right is E,
you need to direct your controller to NE.
On the keyboard, you can just press the 9 on the keypad.
It is much easiler to do it on the keyboard.
If you do it once, you arrow moves to top right.
3) Press Button B or Ctrl until EX is 999.
4) Direct you controler to NE or Keypad 9, seven times until the arrow reach near the 100.
Doing this on NES or Famicom controller is hard but try as many times as you can.
5) Press Button A to get 999 on your Damage.
6) Now with all that EX and Damage, use them to max out your data.
Don't let the 999 on you Cosmo fool you, you can actually store much than that.