[Scenario]

Not tested, but I THINK it will work just fine...

pawn Код:

new
    szName[MAX_PLAYER_NAME],
    szFirstName[MAX_PLAYER_NAME],
    szLastName[MAX_PLAYER_NAME],
    iUnderscorePos;
    
GetPlayerName(playerid, szName, sizeof(szName));
iUnderscorePos = strfind(szName, "_", true);

strmid(szFirstName, szName, 0, iUnderscorePos);
strmid(szLastName, szName, iUnderScorePos+1, MAX_PLAYER_NAME);