Atomic FE uses a file called METADATA.  This file lets you rename the displayed name in the game list  to anything you want.  This can be accessed through the built in config program.  I don't know how MameWah gets the information for its displayed lists, but if it just looks in a a text based file (i.e.  "1941 (J) (rev1.5)= 1941"), you might be able to transfer a custom game config. list that you have created in AtomicFe to MameWah. 
Tek