I am tempted to try some code but I think it will save us all some time if you present your data. Not as a file, but as how you see it being parsed from a file-line to a data structure. In pseudo/abstract-code. Then, along with you, we can see if a hash is a good idea. It seems to me that you thought about how you want your data structure to be but you have some difficulty in doing it in Perl. So talk abstract if you have too.