Originally Posted by
skullpoker
3B9A converted to base 10 is 15258. So if the code works by direct numbers any xp you would normally earn in battle will have 15258 added to the amount. This would be done as adding to FFFF would overflow to very small numbers. So a possible solution, if xp seems to be added to 15258, would be to switch that to FFFF and see if it overflows to low xp.
CA00 is 51712, so that is another possible base, but when you have a 2 line code the first line is sometimes an enabler for the second line. If neither of those numbers seem to be a base to which normal xp is added then you may need to try this from a different angle.
Of course, this is using the XP codes for FFVII as a reference so it could be different in your game.