Showing Month Abbreviation With Using 2 Characters

[AppleofyourEye]

I work in a factory where we use 2 letter month expiry abbreviations. I'm trying to get Excel to show it the same way, but it's limited to Jan, 01, January, etc.
Is there a way I can get it to show JA instead?
We have a spreadsheet that autopopulates a 6 month and 9 month expiration from the current date.
IE 01/12/2013 turns into =M1800+180 (2014/May/30) and =M1800+270 (2014/Aug/28)
So I can't just write a choose/if formula. I'm not sure there's any way of doing this, any help would be appreciated.
(I've attached a copy of an example as well)