Thanks for the help again @CDBlue and @Headrush69
I finally got it working in terms running the Naomi games.
But i'm not clear on something. When i imported the mame folder to C:\ user\Launch Box folder. For the Naomi games like Marvel vs capcom 2 and others, it will not run in LB, even after i change the default emulator from Mame64.exe to Retroarch .
The Naomi games will run no problem if i launch Retroarch outside of LB. Manually opening Retorarch and loading the core (flycast) and loading the content (the specific Naomi rom) from the mame rom folder .
Is there a way to separate the naomi roms from the mame roms, so it knows to use Retroarch emulator (when i'm using LB). Or a working around which doesn't involve me quitting LB and launching Retroarch just to run a few Naomi games.