so index numbers start at 1 and go to 27873 as they are unique identifiers for each announcement. I have a list of 9000 random index numbers so could be anywhere in the range 1-27873 and I want to extract all the columns that are headed by the index numbers. So for example I have index numbers 55, 197, 674, 900 then I want to extract the columns with the headers 55, 197, 674 and 900.