All your batch file will do is:
check if the rom selected in mala is 1942, if it is then goto the MameVerPlus label
check if the rom selected in mala is 1941, if it is then goto the MameVerPlus label
if the game is not 1942 or 1941 then it will go to the default option.
It will not check if the rom is in the folder, it doesnt know anything about it, it will just always go there if you select one of those games from within mala.
you *might* be able to get this to work, but you will need some way of checking if the rom exists within a certain path
and make sure that you have an intelligent way of sorting the roms, verticals and horizontals etc...
Not worth it imo