you can ask me whatever u want
handling custom script is basically direct insert of jass line. and that about player is done like this:
Example
Events
Unit - A unit Starts the effect of an ability
Conditions
Actions
Custom script: set udg_MyInt[ GetPlayerId( GetOwningPlayer( GetTriggerUnit() ) ) ] = some_value
udg = User Defined Global
and that variable MyInt is some integer array...
then i called a few functions let me expalin what they do...
GetTriggerUnit() -> returns unit which casted the spell
GetOwningPlayer( <whichUnit> ) -> returns player which controls the unit
GetPlayerId( <whichPlayer> ) -> returns players id. for example for player red it returns 0, for player blue it returns 1, for player teal returns 2... for neutral passive returns 15
i hope i explained it well
Greets!
~Dark Dragon