while(<DATA>)
{
	my @array = split(/,/);
	print join(',',@array[0..3]),",$array[3],$array[4],",join(',',@array[4..$#array]);
}

__DATA__	
20110_1,1155,30,20110_1_3,0,0,65,0,0,99,20,20,14,0,23,2001-08-01 00:00,2001-09-18 00:00,0,,0,
20110_2,1155,30,20110_2_3,0,0,65,0,0,99,20,20,14,0,23,2001-08-01 00:00,2001-09-18 00:00,0,,0,
20110_3,1155,30,20110_3_3,0,0,65,0,0,99,20,20,14,0,23,2001-08-01 00:00,2001-09-18 00:00,0,,0,