Just a reminder that providing specifics on, sharing links to, or naming websites where ROMs can be accessed is against the rules. If your post has any of this information it will be removed.
Welcome to PokéCommunity! Register now and join one of the best fan communities on the 'net to talk Pokémon and more! We are not affiliated with The Pokémon Company or Nintendo.
It would've been nice if you mentioned that you're specifically talking about pokeemerald-expansion. This forum post has script examples for how you can create custom multi-battles in pokeemerald-expansion. The post is a bit old and it looks like the macros no longer require the back pic parameter.