I believe this is the syntax:
<GAME day="1" time="1905" away="6" home="8" park="1" />
I got that from post #268 in this thread:
https://forums.ootpdevelopments.com/...248744&page=14
You have to know what the park ID is for the neutral park...
If you are able to test this out and make it work, please report back on your steps to get there