BrowserUK, My apologies. It's hard to know how much information to give. Yes, I'm holding back on the details. I try not to bother the monks any more than necessary. I've been programming 30 years & I know SOMETHING. The sloppy posting notwithstanding, my original question was not tech related & I didn't think it req'd code samples. Most other languages have a record format structure. Either thru my ignorance or a design flaw, perl doesn't seem to have one. I was merely asking how best to 'structure' the data I have to read in.

The percentages need to be of the total for around half of the columns. The number of cols doesn't really matter, nor the number of rows. 4 x 24 = 96, but not all stores are open 24hrs, so I averaged. Since I need % of totals, I have to either hold the entire file(s) in ram, or accumulate the totals to a temp file. I'm leaning towards a temp file, but I didn't want to look back & wished I'd asked a smart person. ;-)

The first & last file issues & the yr end rollover are Access issues, not anything to do with the app, BUT... another thing I was saving till I could try on my own... was the fact that we have a file for each day, & I need to let the user pick which files to process, there are no year end totals, as such, just final totals for the 2, 5, 7, or 10 (or more) files selected.

Please bare with me, it's a steep learning curve, & my "doing it for free outside of work' part was only to point out that I may not be able to respond as quickly as I would like & I didn't want you to think you were doing my job for me. We have a vendor coming in this week, & I'll be working days AND evenings most of the week, maybe 2 wks. Sorry for any confusion. I'f you'd like to converse privately, I can send you my email address.

Finaly, yes, I can read/write in perl. I've been studying it about 6 weeks now. The regexs are a hoot, but I'll get a grip on them sooner or later. I like to 'try bfore I cry' (help) ;-)