[SWEMike]

pawn Код:

stock RemoveUnderScore(playerid)
{
    new name[MAX_PLAYER_NAME];
    GetPlayerName(playerid,name,sizeof(name));
    for(new i = 0; i < MAX_PLAYER_NAME; i++)
    {
        if(name[i] == '_') name[i] = ' ';
    }
    return name;
}

Use that function instead of GetPlayerName where you don't want to have the '_', just watch out so you don't change the sections that need names to have underscores.